Mount Sinai and the Sermon on the Mount

Jehovah-Jesus insists that Christ-ians keep His Holy Law (Matt. 5:13-16)

You are the salt of the Earth and need to impart a law-abiding saltiness to an otherwise flavorless and LAWLESS humanity!21 But if the salt gets unsalty, what can give IT saltiness, seeing that saltiness is found in salt ALONE?22 Then, it's no use to anyone — except to be thrown outside and to be trampled on by the men of the world!23 But you are to light up the world!24 A city of God or church universal25 that has been established on Christ the Rock26 on top of a Mountain (like Mount Sinai or                                                       9 Matt. 5:7 cf. Rom. 3:19-31. 10 Matt. 5:8 cf. 15:19. 11 Matt. 5:9a cf. Eph. 2:15-17f & 4:31-32. 12 Matt. 5:9b cf. I John 3:4,9f. 13 Matt. 5:10 cf. Rom. 7:12 & 8:4. 14 Matt. 5:11. Here and frequently elsewhere too we render humeis and humoon by "all of you" and "all of your" respectively in order to distinguish these terms from the singular forms which we simply render "you" and "your," rather than by the archaic "thou" and "thy" and "thine" (which latter, however, for reasons of euphony, we retain in the Sermon on the Mount's explicit or implicit quotations from the Decalogue itself). 15 Matt. 5:11a,33f,44 cf. Ex. 20:7 16 Matt. 5:11b,21-22,44 cf. Ex. 20:13 17 Matt. 5:11c,37 cf. Ex. 20:16. 18 Matt. 5:11c cf. John 15:10,19. 19 Matt. 5:12a cf. Eph. 2:6-10 & Rev. 20:12f & 22:11-15 & Westminster Confession 16:1ab,2c. It should be needless to add that we are, of course, saved not by our own lawkeeping, but by Christ's. For Christ stood in our place and perfectly kept the law for us and perfectly suffered the penalty of our breaking of that law. 20 Matt. 5:12b cf. 23:34-37 & Isa. 57-59 & Jer. 7 & Ezek. 20, etc. 21 Matt. 5:13a cf. Col. 4:6. 22 Matt. 5:13b cf. Mark 9:50. 23 Matt. 5:13c, cf. "men" in vv. 15-16 and the persecutors in vv. 10-12. 24 Matt. 5:14. The thought here is not that Christians are the only light (and a tiny one at that) in an evil world about to overwhelm them, but it is rather that the bright light of Christianity is certain to increase and to illuminate the whole world and the totality of humanity, cf. Matt. 5:14-16 & John 1:4-9 & Isa. 9:1,5-6. 25 Matt. 5:14b cf. Gal. 4:26 & Heb. 11:10,16 & 13:14 & Rev. 21:1-22:19. 26 Matt. 16:18 cf. I Pet. 2:5-8.