How did Abraham know that it was God that bid him offer his son, being a breach of the sixth commandment?

How did Abraham know that it was God that bid him offer his son, being a breach of the sixth commandment?

亚伯拉罕怎么知道是神吩咐他把自己的儿子献上的呢?

-- Anne Hutchinson 安妮·哈钦森