John Gills Exposition of the Bible Commentary - Genesis 9:13
I do set my bow in the cloud ,.... Or "I have given", or "have set it" F16 נתתי "dedi", Montanus; so Ainsworth; "posui", Pisator, Drusius, Buxtorf. ; which seems as if it was at that instant set; this is the same we call the "rainbow": and so Horace F17 De Arte Poetica, ver. 18. calls it "arcus pluvius": it is called a "bow", because of its form, being a semicircle, and a "rainbow", because it is seen in a day of rain, and is a sign of it, or of its being quickly over, Ezekiel... 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