وَأَصْلُهُ فِي اَلصَّحِيحَيْنِ مِنْ حَدِيثِ عَبْدِ اَللَّهِ بْنِ زَيْدٍ
It is originally from the Sahihain of Bukhari and Muslim as the Hadith narrated by Abdullah ibn Zayd.
Bulugh al-Maram 101, Book 1, The Book of Purification, Hadith 101. 1 min read