La Genèse 15:3 Midrash : Midrash Tanchuma, Bereshit Rabbah & Pirkei DeRabbi Eliezer

Another interpretation: "As these nations that you are about to dispossess, etc. but you not like this to you" (Deuteronomy 18:14). It is speaking about Avraham, as he saw through astrology that the constellation said to him that Avram and Sarai would not have a child. What did the Holy One, blessed be He, do for them? Rabbi Yehudah beRabbi Simon said in the name of Rabbi Chanin, "It is written (Genesis 15:5), 'And He took him outside and said, "Observe towards the heavens."' He raised him above the dome of the firmament (above the skies)." As "out" can only [indicate] firmament, as it is stated (Proverbs 8:26), "Before He had made the land and the outside places." And it is also stated (Isaiah 33:7), "Behold the [angels of] Ariel yelled outward." The Holy One, blessed be He, said to him, "That which you said (Genesis 15:3), 'Behold, the one over my household shall inherit me'; the matter is not like this, 'but rather the one who will come out of your innards will inherit you' (Genesis 15:4)." He said [back] to Him, "Are You telling me that I will have a child?" The Holy One, blessed be He, said to him, "Leave your measure! Avram will not have a child, Avraham will have a child; Sarai will not have a child, Sarah will have a child." "And He took him outside." He said to him, "Behold, you are above the constellation. Who is greater than whom? Is it not you, as you are above it?" "Observe towards the heavens." It is not written, "Lift up your eyes towards the heavens," here, but rather "observe." [This] is like a man who observes [what is] below from above. So is it stated (Psalms 13:4), "Observe; answer me, Lord, my God." "And He said to him, 'So will be your seed'" (Genesis 15:5). Moshe said to them, "Just as Avraham left the constellation and did not occupy himself with it, also you." "The Lord, your God, did not give you like this" (Deuteronomy 18:14).

“Abram said: Behold, to me You have not given offspring, and a member of my household is my heir” (Genesis 15:3).
“Abram said: Behold, to me You have not given offspring” – Rav Shmuel bar Rav Yitzḥak said: [Abram said to God:] My astrological constellation is pressuring me and saying to me: Abram, you will not beget offspring. The Holy One blessed be He said to him: ‘Indeed, it is as you say; Abram will not beget offspring, but Abraham will beget offspring. “Sarai your wife, you shall not call her name Sarai” (Genesis 17:15) – Sarai will not bear children, but Sarah will bear children.’

“Behold, the word of the Lord came to him, saying: This man will not inherit you; rather, one who shall emerge from your loins, he will inherit you” (Genesis 15:4).
“Behold, the word of the Lord came to him, saying: This man will not inherit you” – Rabbi Yudan and Rabbi Elazar in the name of Rabbi Yosei bar Zimra: “The Lord to him,” “the word of the Lord came to him,” “behold, the word of the Lord came to him” – one angel after another, one statement after another.³¹There are many seemingly extraneous words here; it could have been, simply: God said. [God said:] ‘I and three angels will reveal ourselves to you, and [we all] say to you: The accursed [luta] Lot will not inherit Abram.’³²Because you will have your own son. The revelation of the three angels refers to Genesis 18:2. Rabbi Huna and Rabbi Elazar in the name of Rabbi Yosei bar Zimra: It is written: “Behold, the word of the Lord came to him” – behold the Lord came, and His speech was with Him.³³The wording should not be understood to imply the revelation of three angels.