Predicting the future

...When those letters were sealed and given to Haman, he and all the members of his entourage proceeded joyfully. They met Mordekhai, who was walking ahead of them. Mordekhai saw three children who were coming from school and Mordekhai ran after them. When Haman and his entire entourage saw that Mordekhai was running after the children, they followed Mordekhai to ascertain what Mordekhai would ask them.
When Mordekhai reached the children, he asked one of them: ‘Recite your verse to me.’ He said to him: ‘“Fear not from sudden terror, and from the cataclysm of the wicked when it comes”’ (Proverbs 3:25). The second began and said: ‘I read today and with this verse I left school: “Take counsel and it will be negated; speak something and it will not stand, as God is with us”’ (Isaiah 8:10). The third began and said: ‘“Until old age I am He and until gray hairs I will bear you; I have done and I will carry; I will bear and I will rescue”’ (Isaiah 46:4).
When Mordekhai heard this, he laughed and was overjoyed. Haman said to him: ‘What is this joy that you rejoiced when hearing the words of these children?’ He said: ‘It is over the good tidings of which they apprised me, that I need not fear the evil designs that you counseled against us.’ Immediately, the wicked Haman became angry and said: ‘I will strike at none other than these children first.

When Rav Sheshet was exiting the house of the Exilarch the servants dug a pit and placed a reed mat [tzifta] on top of it so that the pit would not be noticed. And they said to Rav Sheshet: The Master, i.e., Rav Sheshet, should come and rest for a short time, and they intended for him to fall and be hurt. Rav Ḥisda, who was also present, snorted [neḥar] to him from behind in order to signal to him. Rav Sheshet said to a child who was there: Recite your verse for me that you studied today. The child said to him: “Turn to your right or to your left” (II Samuel 2:21). Rav Sheshet, who was blind, said to his servant: What do you see? His servant said to him: I see a mat that has been placed on the ground. Rav Sheshet said to him: Turn away from it and we will go around it.

After Rav Sheshet left the Exilarch’s house, Rav Ḥisda said to him: From where did the Master, i.e., Rav Sheshet, know that the servants had dug a pit in that place? Rav Sheshet said to him: There were several matters that raised my suspicions. One, that the Master, i.e., Rav Ḥisda, snorted to me to signal that I should beware. And additionally, when the child recited the verse for me it alluded to this matter. And additionally, servants are suspect of not acting according to a high standard, and I suspected that they would attempt to cause me harm.

The Gemara relates that Rav was going to the home of Rav Ḥanan, his son-in-law. He saw that the ferry was coming toward him just when he arrived at the riverbank. He said: The ferry is coming toward me even though I did not arrange for it to come now; this is a sign that a good day, i.e., a festive meal, awaits me in the place where I am going.

After crossing the river on the ferry, Rav went and stood at the gate of Rav Ḥanan’s home. He looked through a crack in the door and saw an animal that was hanging and ready to be cooked. He knocked on the gate, and everyone went out to greet him, and the butchers also came out to greet him. Rav did not remove his eyes from the meat that the butchers were preparing. He said to them: If you had eaten the meat based upon the supervision you provided now, you would have fed forbidden meat to the sons of my daughter because no one apart from me was watching the meat when you all came out to greet me. And despite the fact that he had kept the meat in his sight Rav did not eat from that meat.

The Gemara asks: What is the reason that Rav did not eat the meat? If one suggests that he was concerned because it had been obscured from sight, that cannot be the reason, as Rav kept watching it so that it was not obscured from sight. Rather, Rav did not eat because he divined, i.e., he saw the arrival of the ferry as a good omen. This is prohibited, and therefore Rav penalized himself and abstained from the meat.

The Gemara asks: But doesn’t Rav say that any divination that is not like the divination of Eliezer, the servant of Abraham, when he went to seek a bride for Isaac (see Genesis 24:14), or like the divination of Jonathan, son of Saul, who sought an omen as to whether he and his arms bearer would defeat the Philistines (see I Samuel 14:8–12), is not divination? Since Rav did not rely on the omen in his decision making, he did not violate the prohibition against divination, and there was no reason for him to penalize himself. The Gemara answers: Rather, the reason Rav did not eat the meat is that it was an optional feast, rather than a feast associated with a mitzva, and Rav would not derive pleasure from an optional feast.

Having mentioned Rav’s reaction to the ferry in the incident cited above, the Gemara states that Rav would check whether to travel based upon the ferry; if it came quickly he would take the ferry, but otherwise he would not. And Shmuel would check what would happen to him by opening a scroll and reading from wherever it was open to. Rabbi Yoḥanan would check what was in store for him by asking a child to recite the verse he was learning.

The Gemara relates an incident when Rabbi Yoḥanan checked his luck based on a child’s verse. During all the years when Rav lived in Babylonia, Rabbi Yoḥanan, who lived in Eretz Yisrael, would write to him and begin with the greeting: To our Master who is in Babylonia. When Rav died, Rabbi Yoḥanan would write to Shmuel and begin with the greeting: To our colleague who is in Babylonia. Shmuel said: Does Rabbi Yoḥanan not know any matter in which I am his master? Shmuel wrote and sent to Rabbi Yoḥanan the calculation of the leap years for the next sixty years. Rabbi Yoḥanan was not impressed by this and said: Now he has merely demonstrated that he knows mathematics, which does not make him my master.

Shmuel then wrote and sent to Rabbi Yoḥanan explications of uncertainties pertaining to tereifot that had to be transported on thirteen camels. Rabbi Yoḥanan was impressed by this and said: I have a Master in Babylonia; I will go and see him. Before departing on his journey, Rabbi Yoḥanan said to a child: Recite to me your verse that you studied today. The child recited the following verse to Rabbi Yoḥanan: “Now Samuel was dead” (I Samuel 28:3). Rabbi Yoḥanan said to himself: Learn from this that Shmuel has died. Therefore, Rabbi Yoḥanan did not go to see Shmuel.

The Gemara comments: But it was not so; Shmuel had not died. Rather, the reason Rabbi Yoḥanan was given this sign was so that Rabbi Yoḥanan would not trouble himself to embark on the long and arduous journey from Eretz Yisrael to Babylonia.

It is taught in a baraita: Rabbi Shimon ben Elazar says: With regard to one who is successful with his first business transaction after he has built a home, after the birth of a child, or after he marries a woman, even though he may not use this as a means of divination to decide upon future courses of action, it is an auspicious sign that he will continue to be successful. Conversely, if his first transaction is not successful he may take that as an inauspicious sign.

Rabbi Elazar said: But this is provided that the sign has been established by repeating itself three times. This is based on a verse, as it is written: “And Jacob their father said to them: Me you have bereaved of my children: Joseph is not, and Simeon is not, and you will take Benjamin away; upon me are all these things come” (Genesis 42:36). If calamity were to befall Benjamin, that would establish a pattern of three tragedies.

[A different ruling applies when] a person says, "This dwelling which I built will be a good omen for me"; "This woman whom I married or this animal that I purchased was blessed. From the time I purchased it onward, I have become rich."
The same applies to a person who rejoices and exclaims, "This is a good omen" when he asks a child, "Which verse are you studying?" and the child reads him a verse of blessing. This and the like are permitted, since the person did not perform an act or hold himself back from performing an act [because of the omen]. All he did was consider something that had already happened as a sign.

A child's or a woman's house: even if there is no divinatory benefit, there is a symbol. [Comment of Rema: If one has succeeded afterwards three times, or not (B"Y citing Rashi). And similarly one may say to a child, "Tell me your verse (of current study)" (Tur). Some say that one may make a sign about something that is still to happen, like Eliezer, Abraham's servant did, or Jonathan (Tur and R"D Kimchi) but some forbid it (Rambam and SM"G). But one who proceeds wholeheartedly and trusts in Hashem will be surrounded by kindness.]