Al-Kāfi - Volume 6 > Washing the Head
Hadith #4

مُحَمَّدُ بْنُ يَحْيَى عَنْ مُحَمَّدِ بْنِ الْحُسَيْنِ عَنْ مُوسَى بْنِ سَعْدَانَ عَنْ عَبْدِ اللَّهِ بْنِ سِنَانٍ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ مَنْ أَخَذَ مِنْ شَارِبِهِ وَ قَلَّمَ أَظْفَارَهُ وَ غَسَلَ رَأْسَهُ بِالْخِطْمِيِّ يَوْمَ الْجُمُعَةِ كَانَ كَمَنْ أَعْتَقَ نَسَمَةً .

4. Muhammad ibn Yahya has narrated from Muhammad ibn al-Husayn from Musa ibn Sa‘dan from ‘Abd Allah ibn Sinan who has said the following: “Abu ‘Abd Allah, ‘Alayhi al-Salam, has said, ‘One who trims his fingernails and washes his head with marshmallow plant every Friday is like one who sets free one human soul from bondage and slavery.’”