Midrasch zu Dewarim 2:23

Rabbi Yehoshua of Sichnin in the name of Rabbi Levi opened [with the verse (Tehillim 111:6),] "The power of His works he told to His people [Yisrael]." Why did Hashem reveal to Yisrael that which was created on the first day, and the second day [and so forth]? Because of the idolaters - so that they will not embitter Yisrael and say to them, "Are you not a nation of thieves?" And Yisrael would reply to them, saying, "Aren't your own lands stolen? Didn't (Devarim 2:23) 'The Caphtorim emerge from Caphtor and destroy [the Aviyim] and settle in their stead?' [Furthermore,] the entire world belongs to Hashem; thus, when it pleased Him, He gave it to you, and when it pleased Him, He took it from you and gave it to us." As it is written (Tehillim 111:6), "[In order] to give them an inheritance of the nations," He told [Yisrael] all of the generations.