I call heaven and earth as witnesses against you today that I have set before you life and death, blessing and cursing. Therefore choose life, so that you and your descendants may live,
19. I call heaven and earth to record this day against you. Though the verb is in the past tense, it indicates a present act. It is in order to deal with them with greater urgency that he calls heaven and earth to witness the vengeance of God.
Moses here concludes with a very bright light, and a very strong fire, that, if possible, what he had been preaching of might find entrance into the understanding and affections of this unthinking people. What could be said more moving, and more likely to make deep and lasting impressions?
Commenting on Deuteronomy 30:15-20
I call heaven and earth to record this day against you,.... Either, literally understood, the heavens above him, and the earth on which he stood, those inanimate bodies, which are frequently called upon as witnesses to matters of moment and importance; see Deu 4:26; or figuratively, the inhabitants of both, angels and men: that I have set before you life and death, blessing and cursing...