Midrash sa Mga Kawikaan 22:17: Ein Yaakov (Glick Edition) & Seder Olam Rabbah

But how did R. Mair study the Law from the mouth of Acher? Said Resh Lakish: "R. Mair based his action upon the following passage (Prov. 22, 17) Incline thine ear, and hear the words of the wise, and apply thy heart unto my knowledge. Said R. Chanina, from the following passage (Ps. 45, 11) Hearken, O daughter, and look and incline thy ear, and forget thine own people, and thy father's houses, etc. But do these passages not contradict each other? Nay, the latter refers to a young person, and the former to an adult who cannot distinguish between good and evil. When R. Dimi came, he said: "In the West (Land of Israel) they explained it thus: "R. Mair found a fig (in Acher), he ate the fig, and threw away the peel" (i.e., he picked out the good and threw away the bad teachings). Rabba b. Shila met Elijah and said to him: "What is the Holy One, praised be He! doing?" The latter answered him: "He has uttered doctrine in the name of all other Rabbis, but in the name of R. Mair He has not uttered." "Why so?" "Because he learned doctrine from the mouth of Acher." "Why?" asked R. Shila. "R. Mair found a pomegranate, ate its inside and cast away its husk." He answered him: "He (the Holy One) is at this moment saying: 'Mair, my son says thus: "At the time when men suffer, what does Shechina say? 'I am lighter than my head. I am lighter than my arm'" (i.e., I feel my head heavy — a euphemistic expression). If the Holy One, praised be He! is thus grieved when the blood of wicked men is shed, how much more when the blood of the righteous man is shed!"

... Rabbi Yossi says, "A merit ends up being on a day of merit and a punishment ends up being on a day of punishment. For you will find to say that when the First Temple was destroyed, that day was the culmination of the Shabbat, and it was at the culmination of the sabbatical year and it was during the watch of Yehoyariv and it was the ninth of Av. And likewise with the Second. And in both this one and that one, the Levites were standing on the platform and reciting song. And what song did they recite? 'He will make their evil recoil upon them' (Psalms 94:23)."