This Bible contradiction is from the Skeptic's Annotated Bible.
On Mount Sinai.
Exodus 31:18 View context
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 34:4 View context
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 34:32 View context
And afterward all the children of Israel came nigh: and he gave them in commandment all that the LORD had spoken with him in mount Sinai.
Leviticus 26:46 View context
These [are] the statutes and judgments and laws, which the LORD made between him and the children of Israel in mount Sinai by the hand of Moses.
Leviticus 27:34 View context
These [are] the commandments, which the LORD commanded Moses for the children of Israel in mount Sinai.
Nehemiah 9:13 View context
Thou camest down also upon mount Sinai, and spakest with them from heaven, and gavest them right judgments, and true laws, good statutes and commandments:
On Mount Horeb.
1 Kings 8:9 View context
[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.
2 Chronicles 5:10 View context
[There was] nothing in the ark save the two tables which Moses put [therein] at Horeb, when the LORD made [a covenant] with the children of Israel, when they came out of Egypt.
Malachi 4:4 View context
Remember ye the law of Moses my servant, which I commanded unto him in Horeb for all Israel, [with] the statutes and judgments.