Sifrei Devarim 19

¹(Devarim 1:20) "And I said to you … as the L-rd … has spoken, etc.": Moses said to them: It is not of myself that I speak thus to you, but at the behest of the Holy One Blessed be He. ²"You have come to the mountain of the Emori which the L-rd our G-d gives to us.": An analogy: A king entrusted his son to a pedagogue, who showed him around and said to him: All these vines are yours, and all these vineyards, and all these olive trees. When he tired of showing him, he said to him: Everything that you see is yours. Thus, Moses said to Israel ( Ibid . 8:7) "For the L-rd your G-d is bringing you to a good land, a land of streams of water, fountains and depths, issuing forth in valleys and in mountains." Once they came to the land, he said to them: "You have come to the mountain of the Emori, which the L-rd our G-d gives to us." And if you say the time has not yet arrived. ³(21) "See, the L-rd your G-d has set the land before you." I am telling you not from approximation or from hearsay, but from what you see with your own eyes. "Go up and possess it," immediately, "as the L-rd the G-d of your fathers has spoken to you." I am telling you this not of myself, but by the behest of the Holy One Blessed be He.