Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Ibn Umar (may Allah be pleased with them both) that when the sacrificial animals (hady) were still behind those mountains from which the valley pass (Thaniyyah) could be seen, the polytheists came before the Prophet (peace and blessings be upon him) and turned the direction of his sacrificial animals. So the Messenger of Allah (peace and blessings be upon him) slaughtered them at the very place where the polytheists had stopped him. And this place was Hudaybiyyah. Then the Prophet (peace and blessings be upon him) shaved his head, and the people also followed in his footsteps and had their heads shaved. And some other people waited, and they said: Perhaps we will be able to perform the Tawaf of the House (Ka'bah). Upon this, the Messenger of Allah (peace and blessings be upon him) said: May Allah have mercy on those who shave their heads. It was said to him: And those who shorten their hair...? The Prophet (peace and blessings be upon him) again said: May Allah have mercy on those who shave their heads. He said this three times.