(1) The concerns for which the believer is obligated to put his trust in G-d are of two categories. (1) matters of this world, and (2), matters of Olam Haba (afterlife). And matters of this world subdivide to two divisions.
(2) (1) matters of this world for the benefit of this world. (2) matters of this world for the benefit of the afterlife.
(3) The matters of this world for the benefit of this world subdivide to three parts:
(4) (1) what is beneficial for the body only.
(5) (2) what contributes to one's maintenance or enables one to gain wealth, and various possessions.
(6) (3) what is beneficial for [dealing with] one's household, wife and relatives, for his friends and enemies, and for those above and below him among the various classes of people.
(7) Matters of this world that will secure benefit in Olam Haba subdivide to two parts.
(8) (1) duties of the heart and limbs which relate to oneself only, and whose actions do not result in benefit or damage to others.
(9) (2) duties of the limbs which cannot be done without association with another, where one of them is active and the other is passive. For example, giving charity, acts of kindness, teaching of wisdom, instructing others to do good or to refrain from evil.
(10) Matters of the afterlife subdivide to two parts.
(11) (1) The reward that is deserved.
(12) (2) That which is a special kindness which the Creator bestows to the pious and to the prophets, in Olam Haba. Therefore all things for which one trusts in the Creator fall into 7 categories:
(13) (1) matters of the body alone.
(14) (2) matters of one's possessions and means of earning a livelihood.
(15) (3) matters of one's wife, children, relatives, friends, and enemies [and for those above and below him].
(16) (4) duties of the heart and limbs which only benefit or damage oneself
(17) (5) duties of the limbs which affect others as well, whether benefiting or harming.
(18) (6) reward in the afterlife according to one's conduct in this world.
(19) (7) reward in the afterlife from the Creator in the way of kindness on His treasured ones and those who love Him (i.e. to increase their reward due to their love and clinging to G-d - TL), as written "How great is Your goodness that You have hidden away for those who fear You; You have done for those who trust in You before the sons of men!" (Tehilim 31:20)
(20) Since I have explained the fundamental introductions (in chapter 3) which make it possible for one to place his trust in the Al-mighty, it is proper for me to follow them with an explanation of the proper way of trust in each of the seven categories, through which one should trust in G-d and in something besides Him.
(21) For the first category, matters of the body alone, these are: his life and death, his income for obtaining food, clothing and shelter, his health and illness, his traits. The proper way of trust in the A-lmighty for all of these matters is to submit oneself to the course the Creator has decreed for him in these matters, and to place one's trust in G-d and to know that none of these matters can come to be unless it was previously determined by G-d that this would be the most proper situation for his matter in this world and in Olam Haba (the afterlife), and ultimately the greatest good for him (even if right now it appears to his eye to be not good, certainly, it is the best thing for him for his ultimate end - PL), and that the Creator has exclusive, total control over all of these matters. In none of them can any created being advise any plan, or exercise any control except through His permission, decree, and judgment.
(22) And just like one's life and death, health and sickness, are not in the hands of others, so too, one's livelihood, clothing and other bodily needs are also not in their control.
(23) With clear faith that his matters are given over to the decrees of the Creator, and that the Creator's choice for him is the best choice, it is also his duty to be engaged in means which appear to be beneficial to him and to choose what seems to be the best choice under the circumstances, and the Al-mighty will do according to what He has already pre-decreed.
(24) An example of this: Even though a human being's end and length of his days are determined by the Creator's decree, nevertheless, it is a man's duty to pursue means to survive such as food and drink, clothing, and shelter according to his needs, and he must not leave this to the Al-mighty, and think: "if the Creator has predecreed that I will live, then my body will survive without food all the days of my life, therefore I will not trouble myself in seeking a livelihood and toiling in it".
(25) Likewise, one should not put himself in danger while trusting on the decree of the Creator [that he will live a set time], drinking poisonous drink or going to battle lions or other dangerous animals without necessity, or to cast himself into the sea or into fire, or other similar things that a man is not sure of them and puts his life in danger. And the verse has already warned us in saying "You shall not try the L-ord, your G-d" (Devarim 6:16), because either one of two things will happen.
(26) Either he will die, and it will be considered as if he killed himself, and he will be held accountable for this just as if he had killed another man, despite that his death in this fashion was a decree of the Al-mighty and occurred with His permission.
(27) And we have already been commanded not to murder another human being in any form from the verse "do not murder" (shmot 20:13). And the closer the murdered is to the murderer, the more the punishment should be severe, as written "on pursuing his brother with a sword, corrupting his mercy" (Amos 1:11). And similarly the punishment for one who kills himself will undoubtedly be very great.
(28) This is like a slave whose master commanded him to guard a place for a fixed time, and warned him not to leave the place until his messenger will come. When the slave saw that the messenger was late in coming, he abandoned his post, and the master became furious at him and punished him severely. Similarly, one who causes his own death (by doing dangerous things) moves out of the service of G-d and into rebellion against Him, by putting himself in mortal danger.
(29) This is why you will find Shmuel say (to G-d) "And Shmuel said, "How shall I go? For, if Saul hears, he will kill me." And the L-ord said, "You shall take a heifer with you, and you shall say, 'I have come to slaughter (a sacrifice) to the L-ord.'" (Shmuel I 16:2). And this was not considered a lack of trust in the Al-mighty, and the answer from G-d to him shows that his zeal in this was appropriate (since G-d does not do public miracles without great necessity - TL), and He answered him "You shall take a heifer with you, and you shall say, 'I have come to bring an offering to the L-ord.'" (Shmuel I 16:2), and if this were considered a lack of trust G-d would have answered him "I cause death and grant life. I strike, and I heal" (Devarim 32:39), or something similar, as He answered Moshe when Moshe claimed "But I am slow of speech and slow of tongue" (Shmos 4:10), answering him "Who has made a man's mouth? Who makes a man mute or deaf, seeing or blind". And if Shmuel, with his perfect righteousness did not find it a light matter to put himself to a slight risk of danger, and even though he would be doing so by the command of G-d, as He commanded him "Fill your horn with oil, and go, I shall send you to Jesse, the Bethlehemite, for I have seen for Myself a king among his sons" (Shmuel I 16:1), all the more so for someone not commanded by G-d, that this would be considered reprehensible.
(30) (The second possibility) is that he will be saved by G-d's help. Then his merits will be annulled and he will lose his reward, as our sages said on this matter (Shabbat 32a): "a man should never put himself in danger thinking that a miracle will be performed for him, because maybe no miracle will be done for him, and even if a miracle is done for him, his merits are reduced". And Yaakov our forefather said "I am not worthy from all Your kindnesses" (Bereishis 32:11), to which the targum explains: "my merits have diminished due to all of Your favors and kindnesses."
(31) What we have explained for matters of life and death, also applies to the duty to pursue means for health, food, clothing, shelter, good habits and distancing from their opposite - (to engage in them) while firmly believing that the means to these things do not help at all in attaining them, without the decree of the Creator. Then, when a farmer must plow his field, clear it from weeds, and to sow it, and water it, when rainwater is not available, let him trust in the Creator to make it fertile, and to protect it from plagues, to increase and to bless the crops. And it is not proper to leave the land unworked and unsowed and to trust G-d and rely on His decree that it will grow fruit without being sown first.
(32) And likewise workers, merchants, and contractors are under a duty to pursue their livelihood while trusting in G-d that their livelihood is in His hands and under His control, that He guarantees to provide a man (as the verse "who gives sustenance to all flesh" - PL) and fully provides for him through whatever means He wishes. One should not think that the means can benefit or harm him in the least.
(33) If one's livelihood comes through one of the means he worked on, it is proper for him not to trust in this source, rejoice in it, intensify in it, and turn his heart to it, because this will weaken his trust in the Al-mighty. It is improper to think that this source will be more beneficial to him than what was predecreed from the Creator. He should not rejoice for having pursued and engaged in it. Rather, he should thank the Creator who provided for him after his labor, and that He did not make his work and struggle result in nothing, as written "If you eat the toil of your hands, you are praiseworthy, and it is good for you" (Tehilim 128:2).
(34) A pious man once said: "I am amazed of he who gives to another what the Creator decreed for the latter, and afterwards reminds the latter of the favor he did for him, and seeks to be thanked for this. And I am even more amazed by one who receives his livelihood from another who is forced to provide for him and then submits himself before him, pleases him and praises him."
(35) If one's livelihood fails to come through the means he has worked on, it is possible that the money allocated to him for the day has already reached his hands (and that he doesn't realize it - PL) or that it will come through other means.
(36) However the case, it is proper for him to engage in the means of earning a livelihood and not to be lax in pursuing after them, provided they are suited to his traits and physical abilities, as I previously explained. And all the while, he should trust in G-d, that He will not abandon him (in providing his needs - PL), neglect him (regarding his physical health - PL), or ignore him (in whatever trouble befalls him - PL) as written "The L-ord is good, a stronghold on a day of trouble and knows (Rashi - the needs of) those who trust in Him" (Nachum 1:7).
(37) Similarly, we will say regarding health and sickness. A man is placed under a duty to trust in the Creator in this, while working on maintaining his health according to the means whose nature promotes this, and to fight sickness according to the customary ways, as the Creator commanded "and he shall surely heal him" (shmos 21:19). All of this, without trusting in the means of health or illness that they could help or hurt without the permission of the Creator.
(38) And when one puts his trust in the Creator, He will heal him with or without a means, as written "He sends His word and heals them" (Tehilim 107:20).
(39) It is even possible that He will heal him through something that is normally very harmful, as you know from the story of Elisha and the bad water, that he healed their damaging properties with salt (Melachim II 2:19), and similarly "And G-d showed him a tree and he tossed it into the waters [and the waters became sweet]" (Shmos 15:25), And the midrash tanchuma there explains that this was a bitter, oleander tree. Another example, "let him smear crushed figs on the boils, and he will heal" (Yeshaya 38:21) (and figs normally damage even healthy flesh - PL). And you already know of what happened to the pious king Asa when he trusted in the doctors, and removed his trust in G-d regarding his illness, the sharp rebuke he received for this (i.e. because he did not pray to be healed). And the verse says: "For He brings pain and binds it; He wounds, and His hands heal." (Iyov 5:18).