
(ז) בָּר֣וּךְ הַגֶּ֔בֶר אֲשֶׁ֥ר יִבְטַ֖ח בַּֽיהוָ֑ה וְהָיָ֥ה יְהוָ֖ה מִבְטַחֽוֹ׃
(7) Blessed is the one who places his confidence in YHWH, for YHWH shall be his assurance.
This might help: After a full meal comes something called birkhat hamazon - or, saying "Thank you!" This consists of four different major sections, with each section expressing thanksgiving, requests, and/or praise for things in four different broad categories.
These categories touch upon thanking God for (1) nourishment, (2) for Israel, (3) Jerusalem, and (4) His kindnesses in general.
But we Jews love our praying! And so after finishing the Grace after Meals, many people add on yet ANOTHER series of prayers and praises for good measure.
And that is where this quote from Jeremiah comes in. But since the Grace After Meals has become so long - by the time we get to this quote from Jeremiah, we've been thanking and praising so much that we're about ready to move on to the next thing already! So it's easy to race right through it, completely missing its poetic simplicity.

See the same verse color-coded below.
(ז) בָּר֣וּךְ הַגֶּ֔בֶר אֲשֶׁ֥ר
יִבְטַ֖ח בַּֽיהוָ֑ה וְהָיָ֥ה יְהוָ֖ה מִבְטַחֽוֹ׃
(7) Blessed is the one who:
places his confidence (yivtah) in YHWH; For YHWH shall be his assurance (mivtach-oh).
This is very common in Hebrew poetry; the fancy term is called a chiasmus. While it is structurally pleasing all on its own, I always find myself wondering if there might be some rhetorical intention behind it as well.
And I think that perhaps in this case, there is. For maybe Jeremiah is using using the structure of this line to emphasize how one's end can be mirrored in the beginning. Or more explicitly, as soon as you truly begins trusting in God, you can be all-but-assured that God will ultimately be there for you, to show that your trust was well-placed.

Verses 5-8 make up one poem, which is made up of two strophes, or distinct units.
(ה) כֹּ֣ה ׀ אָמַ֣ר יְהוָ֗ה אָר֤וּר הַגֶּ֙בֶר֙ אֲשֶׁ֣ר יִבְטַ֣ח בָּֽאָדָ֔ם וְשָׂ֥ם בָּשָׂ֖ר זְרֹע֑וֹ וּמִן־יְהוָ֖ה יָס֥וּר לִבּֽוֹ׃ (ו) וְהָיָה֙ כְּעַרְעָ֣ר בָּֽעֲרָבָ֔ה וְלֹ֥א יִרְאֶ֖ה כִּי־יָב֣וֹא ט֑וֹב וְשָׁכַ֤ן חֲרֵרִים֙ בַּמִּדְבָּ֔ר אֶ֥רֶץ מְלֵחָ֖ה וְלֹ֥א תֵשֵֽׁב׃ (ס)
(ז) בָּר֣וּךְ הַגֶּ֔בֶר אֲשֶׁ֥ר יִבְטַ֖ח בַּֽיהוָ֑ה וְהָיָ֥ה יְהוָ֖ה מִבְטַחֽוֹ׃
\(ח) וְהָיָ֞ה כְּעֵ֣ץ ׀ שָׁת֣וּל עַל־מַ֗יִם וְעַל־יוּבַל֙ יְשַׁלַּ֣ח שָֽׁרָשָׁ֔יו וְלֹ֤א ירא [יִרְאֶה֙] כִּֽי־יָבֹ֣א חֹ֔ם וְהָיָ֥ה עָלֵ֖הוּ רַֽעֲנָ֑ן וּבִשְׁנַ֤ת בַּצֹּ֙רֶת֙ לֹ֣א יִדְאָ֔ג וְלֹ֥א יָמִ֖ישׁ מֵעֲשׂ֥וֹת פֶּֽרִי׃
(5) Thus said YHWH: Cursed is the one who trusts in man, who makes mere flesh his strength, and turns his thoughts from YHWH.
(6) He shall be like a bush in the desert, which does not see the coming of good: It dwells in the scorched places of the wilderness, in a barren land without inhabitant.
(7) Blessed is the one who place his confidence in YHWH, for YHWH shall be his assurance.
(8) He shall be like a tree planted by waters, and by a stream it sends forth its roots; It does not fear the coming of heat, and its leaves are ever fresh. During years of drought it does not worry, and it does not cease yielding fruit.
This idea is expressed in many places places elsewhere in TaNaKh. Once place where you might recognize it is in psalms of Hallel, which we recite on Rosh Hodesh and Holidays:
(ה) מִֽן־הַ֭מֵּצַ֥ר קָרָ֣אתִי יָּ֑הּ עָנָ֖נִי בַמֶּרְחָ֣ב יָֽהּ׃
(ו) יְהוָ֣ה לִ֭י לֹ֣א אִירָ֑א מַה־יַּעֲשֶׂ֖ה לִ֣י אָדָֽם׃
(ז) יְהוָ֣ה לִ֭י בְּעֹזְרָ֑י וַ֝אֲנִ֗י אֶרְאֶ֥ה בְשֹׂנְאָֽי׃
(ח) ט֗וֹב לַחֲס֥וֹת בַּיהוָ֑ה מִ֝בְּטֹ֗חַ בָּאָדָֽם׃
(ט) ט֗וֹב לַחֲס֥וֹת בַּיהוָ֑ה מִ֝בְּטֹ֗חַ בִּנְדִיבִֽים׃
(5) In distress I called on YAH; YAH answered me and brought me relief!
(6) YHWH is on my side, I have no fear!; What can mere man do to me?
(7) With YHWH on my side as my helper, I will see the downfall of my foes.
(8) It is better to take refuge in YHWH than to trust in mortals;
(9) It is better to take refuge in YHWH than to trust in royalty.
While placing trust in mortals is like a bush in a barren desert under a scorching son, placing trust in the Almighty is akin to a tree deeply rooted next to a stream, with ever-fresh leaves.
(יח) עֵץ־חַיִּ֣ים הִ֭יא לַמַּחֲזִיקִ֣ים בָּ֑הּ וְֽתֹמְכֶ֥יהָ מְאֻשָּֽׁר׃ (פ)
(18) She (wisdom) is a tree of life to those who grasp her, And whoever holds on to her is happy.
(ב) כִּ֤י אִ֥ם בְּתוֹרַ֥ת יְהוָ֗ה חֶ֫פְצ֥וֹ וּֽבְתוֹרָת֥וֹ יֶהְגֶּ֗ה יוֹמָ֥ם וָלָֽיְלָה׃ (ג) וְֽהָיָ֗ה כְּעֵץ֮ שָׁת֪וּל עַֽל־פַּלְגֵ֫י מָ֥יִם אֲשֶׁ֤ר פִּרְי֨וֹ ׀ יִתֵּ֬ן בְּעִתּ֗וֹ וְעָלֵ֥הוּ לֹֽא־יִבּ֑וֹל וְכֹ֖ל אֲשֶׁר־יַעֲשֶׂ֣ה יַצְלִֽיחַ׃
(2) The teaching of YHWH is his [the happy person's] delight, and he studies that teaching day and night.
(3) He is like a tree planted beside streams of water, which yields its fruit in season, whose foliage never fades, and whatever it produces thrives.

In the Psalter's case, the key to being guaranteed an abundance of water and healthy foliage is "The teaching of YHWH;" i.e., wisdom. Whereas in Jeremiah's case, the key is trusting in God! Wisdom and Trust - both important, but definitely not the same.
One might not be endowed with, or have accumulated "wisdom," and yet might still place most or all of his/her trust fully in God. And on the other hand, one might place no trust in God, and be very knowledgeable about the teachings of God! Right?
- Are Jeremiah and the psalter each providing two different yet legitimate paths of being able to live a life of security?
- Are they both telling us one piece of the things we should work for, but they would both say that both wisdom and trust are necessary?
- Are they disagreeing - such that Jeremiah says that to pursue trust in God is the most important, whereas the psalter says better to pursue "wisdom" of God?
- Should we attempt to harmonize, and say that the two cannot help but go together? For perhaps the Torah's very definition of wisdom is, in fact, trusting in God!

But even so ! - anyone can take a first step; And in my opinion, the first step towards either of these could be just going ahead and opening up a TaNaKh to just about any chapter, and engaging in active reading. Not only pursuing comprehension, but thinking deeply, critically, questioning, and meditating on the words, poems, prophecies, and stories.

While in pursuit of trust, you can probably open up to, well, just about anywhere! The most frequently mentioned commandment in the TaNaKh, which comes up over 100 times (!), is אל תירא - have no fear! I have found that the trust that our Israelite ancestors had in God is so incredibly communicable ! - particularly throughout the psalms.
This is not to say that all you have to do is read a bit here, read a bit there and bam! you'll find you've gotten there just like that. As I said above, we are speaking about possible first steps. I dare say that if someone reads TaNaKh with an open heart as well as a desire that their trust in God - or in Hebrew, their בטחון (bitahon) or אמונה (emunah) will start to evolve - then with time, it will.


