Bar Yochai, the Rainbow, and the Thirty Righteous of the World

For example: Rabbi Yudah bar Giyora and Rabbi Isaac and Rabbi Nathan went to hear the section concerning the drink offerings from Rabbi Simeon ben Yohai, and they remained there three days. They said: We must take leave. On the first day they entered before him and he expounded, "I do set my bow in the cloud" (Genesis 9:13); Rabbi Simeon ben Yohai said: It is a sign for the world. On the second day he expounded, "and the bow shall be seen in the cloud" (Genesis 9:14); Rabbi Simeon ben Yohai said: It is a sign for the world. Rabbi Hezekiah in the name of Rabbi Jeremiah: Thus would Rabbi Simeon ben Yohai say: O valley, valley, fill yourself with golden dinars, and it would fill up. Rabbi Hezekiah in the name of Rabbi Jeremiah: Elijah, may he be remembered for good, and Rabbi Joshua ben Levi were sitting and studying. They came upon a certain teaching in the name of Rabbi Simeon ben Yohai. Rabbi Simeon ben Yohai passed by. They said: Here comes the master of the teaching; let us arise and ask him about it. They arose and asked him. He said to him: Who is this who is with you? He said to him: He is Rabbi Joshua ben Levi, and he is the greatest man of the generation. He said to him: And has the rainbow appeared in his days? He said to him: Yes. He said to him: If the rainbow has appeared in his days, he is not worthy to behold the sight of my countenance. Rabbi Hezekiah in the name of Rabbi Jeremiah: Thus would Rabbi Simeon ben Yohai say: The Holy One, blessed be He, swore to our father Abraham that the world should never have fewer than thirty righteous men like himself. And what is the reason? "And Abraham shall surely become (hayoh yihyeh)" (Genesis 18:18). [The letters of yihyeh are counted as numerical values:] yod is ten, heh is five, yod is ten, heh is five, which makes thirty. And if there is only one, I am he. Rabbi Hezekiah in the name of Rabbi Jeremiah: Thus would Rabbi Simeon ben Yohai say: Let Abraham bring near from his side up to my own, and I will bring near from my side until the King Messiah comes. And if not, let Ahijah the Shilonite join with me, and we will bring near the whole world. On the third day he expounded, "And he said, Go, sell the oil" (2 Kings 4:7).