Al-Kāfi - Volume 6 > Clipping the finger Nails
Hadith #16

عَلِيُّ بْنُ إِبْرَاهِيمَ عَنْ أَبِيهِ عَنِ ابْنِ أَبِي عُمَيْرٍ رَفَعَهُ فِي قَصِّ الْأَظْفَارِ تَبْدَأُ بِخِنْصِرِ الْأَيْسَرِ ثُمَّ تَخْتِمُ بِالْيَمِينِ .

16. Ali ibn Ibrahim has narrated from his father from ibn abu ‘Umayr from in a marfu‘ manner has said the following: “When clipping fingernails you must begin with the little finger of the left hand and complete it with the right hand (little fingernail).’”