Moses, like Abraham, was a great intercessor.  He was the one whom the Lord spoke to face to face just as a man speaks to his friend.

Now when Moses was upon Mount Sinai receiving Gods laws, the people down below concluded that he had died since he had been gone so long.  For this reason, they persuaded Aaron to make a golden calf; and they worshiped it, and sacrificed to it; and they corrupted themselves with alcohol and immoral activity. Here is the Scripture reference in Exodus 32:7-14:

Then the Lord spoke to Moses, “Go down at once, for your people, whom you brought up from the land of Egypt, have corrupted themselves. 8 They have quickly turned aside from the way which I commanded them. They have made for themselves a molten calf, and have worshiped it, and have sacrificed to it, and said, ‘This is your god…