عَن بُريدةَ
قَالَ: كُنَّا فِي الْجَاهِلَيَّةِ إِذَا وُلِدَ لِأَحَدِنَا غلامٌ ذَبَحَ شاةٌ ولطَّخَ رأسَه بدمه فَلَمَّا جَاءَ الْإِسْلَامُ كُنَّا نَذْبَحُ الشَّاةَ يَوْمَ السَّابِعِ وَنَحْلِقُ رَأْسَهُ وَنُلَطِّخُهُ بِزَعْفَرَانٍ
When a boy was born to one of us in the pre-Islamic period he sacrificed a sheep and smeared his head with its blood; but when Islam came we sacrificed a sheep on the seventh day, shaved his head and smeared it with saffron. Abu Dawud transmitted it, and Razin added, “and gave him his name.”
Mishkat al-Masabih 3992, Book 21, Game and Animals Which May Be Slaughtered, Hadith 93. 1 min read