Midrash su Genesi 22:15

"And the angel of Ad-nai called to Avraham a second time from heaven, and said: 'By Myself I have sworn" (Gen. 22:15-16). Why was this oath needed? He [Avraham] said to Him: ‘Swear to me not to test me ever again, nor my son Itzchak.’ This is similar to one who was saving his basin from being swallowed by the river, and his son jumped into it with him. Another interpretation: why was this oath needed? Rabbi Chama ben Rabbi Chanina said: He said to Him ‘swear to me not to test me ever again’ This is similar to a king who was married to a noble lady, she gave birth to her first son and he divorced her; [he remarried her and then she gave birth to] a second son, and he divorced her; a third son, and he divorced her; and when she gave birth to the tenth son, they all assembled and demanded of him: ‘Swear to us not to divorce our mother ever again.’ So too when our father Avraham was tested the tenth time, he said to Him: ‘Swear to me that You will not to test me ever again.’ Rabbi Chanin said: "Because you have done [asita] this thing" (Gen. 22:17) — it was the tenth [asiri] trial, and you say "because you have done this thing!" Rather, this is the last test, which was as weighty as all the rest together, and if he had not accepted to [do] it, all would have been lost. [A different version: all that he did would have been lost.] "I will verily bless you, etc." (Gen. 22:17) a blessing for the father and a blessing for the son. "And I will verily multiply"(Gen. 22:17) : increase for the father and increase for the son. "And your seed shall inherit the gate of his enemies"(Gen. 22:17). Rabbi said: This is Tadmor, happy is anyone who sees the downfall of Tadmor which took part in both destructions. Rabbi Yudan and R. Chanina — one of them said 'at the destruction of the first Temple it supplied eighty thousand archers.[A different version: truth tellers (?)] and in the second destruction it supplied eight thousand archers. "And Avraham returned to his young men (Gen. 22:19) And where was Itzchak? Rabbi Berechiah said in the name of the Rabbis from there: he sent him to Shem to study Torah. This is similar to a woman who became wealthy through her spindle, she said: ‘Since I have become wealthy through this spindle, it will never leave my hand.’ So too Avraham said: ‘All that has happened to me is only because I engaged in Torah and mitzvot; so I do not want it to ever depart from my seed.’ Rabbi Chanina said: He sent him [home] at night, for fear of the [evil] eye, because from the moment that Chananiah, Mishael, and Azariah came out unscathed from the fiery furnace they aren't mentioned anymore, and where did they go? Rabbi Eleazar said: They died through the spittle. Rabbi Yosei said: They died through an [evil] eye. Rabbi Yehoshua ben Levi said: They changed their place and went to Yehoshua ben Yehotzadak to study Torah, since it is written "Hear now, Yehoshua the high priest, you, and your companions that sit before you [for they are men that are a sign] (Zech. 3:8). Rabbi Chanina said: For this Chananiah, Mishael, and Azariah went down to the fiery furnace, that a sign should be done through them.