Exodus 32:30 in the King James Version
And it came to pass on the morrow, that Moses said unto the people, Ye have sinned a great sin: and now I will go up unto the LORD; peradventure I shall make an atonement for your sin.
Context
29 Moses said, “Consecrate yourselves today to the LORD, for every man was against his son and against his brother, that he may give you a blessing today.”
30 On the next day, Moses said to the people, “You have sinned a great sin. Now I will go up to the LORD. Perhaps I shall make atonement for your sin.”
31 Moses returned to the LORD, and said, “Oh, this people have sinned a great sin, and have made themselves gods of gold.