After laying down the fundamental condition of a proper relation towards God, Moses describes the fear of God, i.e., true reverence of God, in its threefold manifestation, in deed (serving God), in heart (cleaving to Him; cf. Deu 4:4), and with the mouth (swearing by His name; cf. Deu 6:13). Such reverence as this Israel owed to its God; for “He is thy praise, and He is thy God” (Deu 10:21). He has given thee strong inducements to praise. By the great and terrible things which thine eyes have seen, He has manifested Himself as God to thee. “Terrible things” are those acts of divine omnipotence, which fill men with fear and trembling at the majesty of the Almighty (cf. Exo 15:11). אִתְּךָ עָשָׂה, “done with thee,” i.e., shown to thee (אֵת in the sense of practical help).