Midrash su Geremia 15:19

Rabbi once happened to come to the city where R. Tarphon used to dwell, and asked: "Has the man who used to swear by his children left a son?" And he was told that he had left no son, but a grandson of his daughter, and that he was so beautiful that even prostitutes whose price was two dinars would pay four to him. He sent for him, and said: "If you will repent, I shall give you my daughter." And he did so. According to some, he married Rabbi's daughter, but divorced her afterwards; and according to others, he did not marry her at all, so that people should not say that he repented only for the sake of this woman. But what was the reason that Rabbi troubled himself so much in such cases? R. Juda said in the name of Rab, according to others, R. Chiya b. Abba said in the name of R. Jochanan, and according to still others, R. Samuel b. Nachmeni said in the name of R. Jonathan: "He who teaches the Torah to the son of his neighbor will be rewarded with a seat in the heavenly college; as it is said (Jer. 15, 19) Behold, thus said the Lord… . Thou shalt stand before me, and if thou bring forth the precious from the vile, thou shall be as my mouth. And he who teaches the Torah to the son of an Am Ha'aretz, even if the Holy One, praised be He, ordained an evil decree against the world. He will abolish it [for the sake of this meritorious act]; as it is said (Ib.) And if thou bring forth the precious from the vile."

(Ibid.) "And Israel dwelt … alone": Not "alone" as in (Jeremiah 15:19) "Because of Your hand I sat alone." And not "alone" as in the words of that wicked one (Bilam, Bamidbar 23:9) "Lo, the people (Israel) shall dwell alone" (in the world). But as "alone" in the words of Moses (Devarim 32:12) "The L-rd alone led them, no strange god with Him."