It is narrated from Sayyiduna Abu Maryam (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said in one of his sermons: "O Allah, forgive those who shave their heads." A man said: O Messenger of Allah! And those who shorten their hair too. (He said this) three times, and the Prophet (peace and blessings be upon him) (finally) said: "And those who shorten their hair too."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 16653