And God said, This is the token— אוֹת (vide Genesis 1:14; Genesis 4:15)—of the covenant which I make—literally, am giving (cf. Genesis 17:2)—between me and you and every living creature that is with you, for perpetual generations.
Le'doroth (vide Genesis 6:9); 'olam (from 'alam, to hide, to conceal), pr. that which is hidden; hence, specially, time of which either the beginning or the end is uncertain or undefined, the duration being usually determined by the nature of the case (vide Gesenius, 'Hebrews Lex.
,' sub voce). Here the meaning is, that so long as there were circuits or generations of men upon the earth, so long would this covenant endure.