Hadith 3:128
‘Abdallah b. Zaid said that God’s messenger performed the details of ablution twice each, and said, “It was a light upon a light.”
وَعَنْ عَبْدِ اللَّهِ بْنِ زَيْدٍ قَالَ: إِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ تَوَضَّأ مَرَّتَيْنِ مَرَّتَيْنِ وَقَالَ: هُوَ «نُورٌ عَلَى نُورٍ»
Original Reference: Mishkat al-Masabih 423