Midrasch zu Amos 6:13

And when Israel prospers, the nations dissimulate, presenting themselves as "brothers." As Esav said to Jacob (Bereshith 33:9) "My brother, let there be yours what is yours." And thus did Chiram say to Solomon (I Kings 9:13) "What are these cities that you have given me, my brother?" (Devarim, Ibid.) "Lest they say: 'Our hand is exalted, etc.'" as in (Amos 6:13) "Behold, with our strength we have taken power for ourselves." (Devarim, Ibid. 28) "For it is a nation devoid of counsel":