New Defender's Study Bible Notes
9 Michael the archangel. This fascinating incident is never mentioned elsewhere in Scripture; in fact, the burial place of Moses is said to be known only to the Lord (Deuteronomy 34:6). However, a pseudepigraphical work called The Assumption of Moses, preserved now only as a fragment, seems to have recorded the story, and Jude may either have obtained it from that source or else have received it by direct revelation. In either case, its inclusion in Jude’s inspired epistle is enough to confirm its actual occurrence. Satan evidently wanted the body of Moses for some purpose involving deception of God’s people, hoping perhaps to lead them to doubt God again or even to lapse back into idolatry, worshipping Moses’ body or some idol spirit professing to be Moses. No one knows, but in any case God would not allow it, and He Himself buried Moses in a secret grave.
9 railing accusation. The reason why Jude introduced this event in his epistle was to stress the dangerous impropriety of speaking evil or speaking disdainfully of exalted angels in God’s hierarchy of creation, let alone of God Himself. Michael is one of God’s archangels, yet Satan (i.e., Lucifer) had once been the highest of all, as the anointed cherub over God’s throne (Ezekiel 28:14). Even though he had fallen from heaven, he was still treated with great respect by Michael when contending with him.
9 The Lord rebuke thee. See Zechariah 3:2 for a very similar response to Satan when disputing about God’s high priest.