To shave the head and to have the head-hair cut short on finishing the Ihram

Narrated Abu Huraira: Allah's Messenger (ﷺ) said, "O Allah! Forgive those who get their heads shaved." The people asked. "Also those who get their hair cut short?" The Prophet (ﷺ) said, "O Allah! Forgive those who have their heads shaved." The people said, "Also those who get their hair cut short?" The Prophet (invoke Allah for those who have their heads shaved and) at the third time said, "also (forgive) those who get their hair cut short."