Midrasch zu Dewarim 4:8

13...

Unto the land that I will show you (Gen. 12:1). The Holy One, blessed be He, did not mention any specific place. This indicates that this was a trial within a trial, as in the case of a man who embarks upon a journey without being aware of his destination. What did Abraham do? He took his possessions and his wife and departed: And Abraham went, as the Lord had spoken to him (ibid., v. 4). And I will make of thee a great nation (ibid., v. 2). It is not written “I will establish you up as a great nation,” but I will make you a great nation; that is, I will create anew, as indicated by the verse And God made the firmament (ibid. 1:7); And God made the two great lights (ibid., v. 16). R. Phinehas the priest, the son of Hama said: When did the Holy One, blessed be He, make Abraham into a great nation? He did so when Israel accepted the Torah. Thus Moses proclaimed concerning them: For what great nation is there (Deut. 4:8).

Another interpretation (of Ps. 32:8): LET ME INSTRUCT YOU AND TEACH YOU. What is the meaning of AND TEACH YOU? < AND TEACH YOU THE WAY TO GO >, (according to Gen. 12:1) UNTO THE LAND THAT I WILL SHOW YOU. He said to Abraham: You are not losing out. FOR (according to vs. 2) I WILL MAKE YOU INTO A GREAT NATION.¹⁷Gen. R. 39:11; Numb. R. 11:2. "For I will establish you" is not written here but FOR I WILL MAKE YOU, because I creating you as a new creature. In the same sense it is stated (in Gen. 1:7): AND GOD MADE THE FIRMAMENT. < Similarly > (in vs. 16): AND GOD MADE THE TWO < GREAT > LIGHTS. R. {Minhas} [Pinhas] bar Hama [the Priest] said: When did the Holy One make Abraham a great nation? When Israel had left Egypt, come to Sinai, and received the Torah, Moses looked at them and said: Behold, they have been made just as the Holy One had promised to the patriarch. Thus it is stated (in Deut. 4:8): AND WHAT GREAT NATION….