Daraqutni

Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) narrates: I remember this about the Prophet (peace and blessings be upon him), that he was in Mina on his camel, when a man came to him and said, "O Messenger of Allah! I thought that the head is to be shaved before offering the sacrifice, so I shaved my head before offering the sacrifice." The Prophet (peace and blessings be upon him) said, "Now offer your sacrifice, there is no harm." The narrator says: Another man came to the Prophet (peace and blessings be upon him) and said, "O Messenger of Allah! I thought that the head should be shaved before throwing the pebbles, so I shaved my head before throwing the pebbles." The Prophet (peace and blessings be upon him) said, "Now throw the pebbles, there is no harm." The narrator says: On that day, whatever the Prophet (peace and blessings be upon him) was asked about—whether a person had done something before or after its due time—the Prophet (peace and blessings be upon him) said, "Now do it, there is no harm." The same narration is also transmitted with another chain, but in it these additional words are present: "He departed before throwing the pebbles." These words have not been corroborated by other narrators, and I think the narrator made a mistake in transmitting these words.