John Gill Commentary Deuteronomy 16:12

"And thou shalt remember that thou wast a bondman in Egypt: and thou shalt observe and do these statutes." — Deuteronomy 16:12 (ASV)

And you shall remember that you were a bondman in Egypt ,
&c.] And now delivered from that bondage; the consideration of which should make them liberal in their freewill offering, and generous in the feast they provided, and compassionate to the stranger, widow, and fatherless:

and you shall observe and do these statutes ;
concerning the passover, the feast of unleavened bread, and of Pentecost, and the peace offerings and the freewill offerings belonging to them: and nothing could more strongly oblige them to observe them than their redemption from their bondage in Egypt; as nothing more engages to the performance of good works than the consideration of our spiritual and eternal redemption by Christ, (1 Corinthians 6:19 1 Corinthians 6:20) (Titus 1:14) (1 Peter 1:17–19) .