This Bible contradiction is from the Skeptic's Annotated Bible.
Exodus 34:1 View context
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 thou brakest.
Exodus 34:27 View context
And the LORD said unto Moses, Write thou these words: for after the tenor of these words I have made a covenant with thee and with Israel.