The tablets are the covenants — God's promise to save and bless humans on condition of
obedience as outlined.
In making such a covenant, God was solemnly invoked as a witness, Gen 31:50, and an oath was sworn.
Gen 21:31. A sign or witness of the covenant was sometimes made of a pillar or heap of stones
being erected, Gen 31:52, in this case stone tablets that testify against God's
people.
First Set
Exodus 24:12 "And the LORD said unto Moses, Come up to me into the mount, and be there: and I will give thee tables of stone, and a law, and commandments which I have written; that you may teach them."
Exodus 25:16 "And you shall put into the ark the testimony which I shall give thee."
Exodus 31:18 "And he gave unto Moses, when he had made an end of communing with him upon mount Sinai, two tables of testimony, tables of stone, written with the finger of God."
Exodus 32:15-16 "And Moses turned, and went down from the mount, and the two tables of the testimony were in his hand: the tables were written on both their sides; on the one side and on the other were they written. And the tables were the work of God, and the writing was the writing of God, graven upon the tables."
Exodus 32:19 "And it came to pass, as soon as he came nigh unto the camp, that he saw the calf, and the dancing: and Moses' anger waxed hot, and he cast the tables out of his hands, and brake them beneath the mount."
Deuteronomy 5:7-22 "Thou shalt have none other gods before me. Thou shalt not make thee any graven image, or any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the waters beneath the earth: Thou shalt not bow down thyself unto them, nor serve them: for I the LORD thy God am a jealous God, visiting the iniquity of the fathers upon the children unto the third and fourth generation of them that hate me, And shewing mercy unto thousands of them that love me and keep my commandments. Thou shalt not take the name of the LORD thy God in vain: for the LORD will not hold him guiltless that taketh his name in vain. Keep the sabbath day to sanctify it, as the LORD thy God hath commanded thee. Six days thou shalt labour, and do all thy work: But the seventh day is the sabbath of the LORD thy God: in it thou shalt not do any work, thou, nor thy son, nor thy daughter, nor thy manservant, nor thy maidservant, nor thine ox, nor thine ass, nor any of thy cattle, nor thy stranger that is within thy gates; that thy manservant and thy maidservant may rest as well as thou. And remember that thou wast a servant in the land of Egypt, and that the LORD thy God brought thee out thence through a mighty hand and by a stretched out arm: therefore the LORD thy God commanded thee to keep the sabbath day. Honour thy father and thy mother, as the LORD thy God hath commanded thee; that thy days may be prolonged, and that it may go well with thee, in the land which the LORD thy God giveth thee. Thou shalt not murder. Neither shalt thou commit adultery. Neither shalt thou steal. Neither shalt thou bear false witness against thy neighbour. Neither shalt thou desire thy neighbour's wife, neither shalt thou covet thy neighbour's house, his field, or his manservant, or his maidservant, his ox, or his ass, or any thing that is thy neighbour's. These words the LORD spake unto all your assembly in the mount out of the midst of the fire, of the cloud, and of the thick darkness, with a great voice: and he added no more. And he wrote them in two tables of stone, and delivered them unto me."
Second Set
There was a second set of tablets made after Moses destroyed the first set.
Exodus 34:1-4 "And the LORD said unto Moses, Hew thee two tables of stone like unto the first: and I will write upon these tables the words that were in the first tables, which you broke...And he hewed two tables of stone like unto the first; and Moses rose up early in the morning, and went up unto mount Sinai, as the LORD had commanded him, and took in his hand the two tables of stone."
Exodus 34:28-29 "And he was there with the LORD forty days and forty nights; he did neither eat bread, nor drink water. And he wrote upon the tables the words of the covenant, the ten commandments. And it came to pass, when Moses came down from mount Sinai with the two tables of testimony in Moses' hand, when he came down from the mount, that Moses wist not that the skin of his face shone while he talked with him."
Deuteronomy 4:13 "And he declared unto you his covenant, which he commanded you to perform, even ten commandments; and he wrote them upon two tables of stone."
Deuteronomy 10:1-2 "At that time the LORD said unto me, Hew thee two tables of stone like unto the first, and come up unto me into the mount, and make thee an ark of wood. And I will write on the tables the words that were in the first tables which thou brakest, and thou shalt put them in the ark. "
1 Kings 8:9 "There was nothing in the ark save the two tables of stone, which Moses put there at Horeb, when the LORD made a covenant with the children of Israel, when they came out of the land of Egypt."