Rabbi said: The Holy One, blessed be He, brought Abraham outside (his house) on the night of Passover, and He said to him: Abraham! Hast thou the ability to count all the host of heaven? He said before Him: Sovereign of all worlds! Is there then a limit to Thy troops (of angels)? He said to him: Likewise thy seed shall not be counted owing to their great number, as it is said, "And he said unto him, So shall thy seed be" (Gen. 15:5).
Rabbi Eliezer said: The Holy One, blessed be He, showed to our father Abraham (at the covenant) between the pieces the four kingdoms, their dominion and their downfall, as it is said, "And he said unto him, Take me an heifer of three years old, and a she-goat of three years old" (Gen. 15:9). "An heifer of three years old" (ibid.) refers to the kingdom of Edom, which is like the heifer of a sheep. "And a she-goat of three years old" (ibid.) refers to the kingdom of Greece, as it is said, "And the he-goat magnified himself exceedingly" (Dan. 8:8). "And a ram of three years old" (Gen. 15:9); this is the kingdom of Media and Persia, as it is said, "And the ram which thou sawest that had the two horns, they are the kings of Media and Persia" (Dan. 8:20). "And a turtle-dove" (Gen. 15:9); this refers to the sons of Ishmael. This expression is not to be understood in the literal meaning of Tôr (turtle-dove), but in the Aramaic language, in which Tôr means Ox, for when the male ox is harnessed to the female, they will open and break all the valleys, even as it says (about) "the fourth beast" (Dan. 7:19). "And a young pigeon" (Gen. 15:9); this refers to the Israelites, who are compared || to a young pigeon, as it is said, "O my dove, thou art in the clefts of the rock" (Cant. 2:14). For thy voice is pleasant in prayer, and thy appearance is beautiful in good deeds. "And a young pigeon" (Gen. 15:9); this refers to the Israelites, who are compared to a young pigeon: "My dove, my perfect (one), is (but) one" (Cant. 6:9).