And it shall come to pass, when many evils and troubles are befallen them,.... As did in the times of the judges, in the Babylonish captivity, and do now in their present exile: that this song shall testify against them as a witness; which so clearly points at their sins, with all their aggravated circumstances, and describes so fully their calamities, distresses, and punishment for them: for it shall not be forgotten out of the mouths of their seed; which shows that it respects time to come, their later posterity, whose memory of this song would be conjured up by the evils that should come upon them for their sins; nor is it forgotten by them to this day, who acknowledge there are some things in it now fulfilled or fulfilling in them: for I know their imagination which they go about even now: or are "making" (c); forming and framing within themselves, there being a secret inclination in their minds to idolatry, which were working and contriving schemes to bring it about, and set it up; and this, God, the searcher of hearts, knew full well, and that in process of time this evil imagination would break forth into act, in an open and flagrant manner: before I have brought thee into the land which I sware; to their fathers, to give it to them for an inheritance, as is suggested in Deu 31:20. (c) "faciens", Montanus; "quam facit", Pagninus.