John Gills Exposition of the Bible Commentary - Genesis 9:17
And God said to Noah, this is the token of the covenant ,.... Which is repeated for the greater confirmation and certainty of it, since the fears of men would be apt to run very high, especially while the flood was fresh in memory: which I have established between me and all flesh that is upon the earth : see Genesis 9:9 , it is highly probable, that from the rainbow being the token of the covenant between God and Noah, and the creatures, sprung the fable of the Chinese concerning... read more
Matthew Henry's Complete Commentary - Genesis 9:12-17
Articles of agreement among men are usually sealed, that the covenants may be the more solemn, and the performances of the covenants the more sure, to mutual satisfaction. God therefore, being willing more abundantly to show to the heirs of promise the immutability of his councils, has confirmed his covenant by a seal (Heb. 6:17), which makes the foundations we build on stand sure, 2 Tim. 2:19. The seal of this covenant of nature was natural enough; it was the rainbow, which, it is likely, was... read more