Midrash for Amos 4:2

We find that the Holy One, blessed be He, said to Noah: Neither shall there anymore be a flood (Gen. 8:11). Isaiah later explained that this was an oath, as it is said: For as I have sworn that the waters of Noah shall no more go over the earth (Isa. 54:9), and that this promise will be fulfilled everlastingly. How much more so, then, will He keep the three oaths that He explicitly swore to Israel. The first oath was: So have I sworn that I would not be wroth with thee nor rebuke thee (ibid.); the second was: The Lord God has sworn by His holiness (Amos 4:2); and the third was: The Lord God has sworn by His right hand, and by the arm of His strength: Surely I will no more give thy corn to be food for thine enemies (Isa. 62:8).