Volume 2, Book 26, Number 785:
Narrated Abdullah bin Umar:
Allah’s Apostle said, “O Allah! Be merciful to those who have their head shaved.” The people said,
“O Allah’s Apostle! And (invoke Allah for) those who get their hair cut short.” The Prophet said, “O
Allah! Be merciful to those who have their head shaved.” The people said, “O Allah’s Apostle! And
those who get their hair cut short.” The Prophet said (the third time), “And to those who get their hair
cut short.” Nafi’ said that the Prophet had said once or twice, “O Allah! Be merciful to those who get
their head shaved,” and on the fourth time he added, “And to those who have their hair cut short.”