It was the practice of the Prophet (peace and blessings be upon him):
"He (peace and blessings be upon him) was the most merciful of all people towards children and family."
Hadith Referenceصحیح الجامع الصغیر / حرف الكاف / 4797
Hadith Gradingالألبانی:صحيح
Hadith Takhrij[ابن عساكر] عن أنس. الصحيحة ٢٠٨٩: م، أبو الشيخ.