Deuteronomy 5:15

A different reason for the keeping of the Sabbath from that given in Exodus 20:11. It is relevant to D's addition in the previous v., and at first seems intended only to enforce the extension of the Sabbath-law to slaves, remember thou wast a bondman in the land of Egypt and Jehovah thy God brought thee out; but before it closes it bases the whole observance of the Sabbath on the deliverance from Egypt as if the S. were a memorial of that event wherefore Jehovah thy God hath commanded thee to keep the S. day. This historical reference and the humanity enforced by it are characteristic of D. But Exodus 20:11, under the influence of P, recites as the motive for the observance of the S. God's rest on the seventh day from the work of creation. The influence of P on Ex. proves the D form to be the more original. Note that while it enforces the philanthropic motive for Sabbath-observance it is as theological as the other, and, like it, refers to God's action as the ultimate sanction of the Sabbath.

remember that thou wast a bondman] The same motive is expressed for the laws enforcing liberality to slaves, Deuteronomy 15:15; the duty of sharing the joy of the feasts with needy dependents, Deuteronomy 16:12; and justice and generosity to the poor, Deuteronomy 24:18; Deuteronomy 24:22.

a mighty hand and … a stretched out arm See on Deuteronomy 4:34.

to keep lit. to door make, i.e. to carry into effect; used by D also of the Passover, Deuteronomy 16:1; more frequently in P: of the Sabbath, Exodus 31:16; of the Passover, Exodus 12:47 f.; Numbers 9:4-6, etc.