Al-Kāfi

Hadith 2073
health-hygiene
أَبُو عَلِيٍّ الْأَشْعَرِيُّ عَنْ بَعْضِ أَصْحَابِهِ عَنْ مُحَمَّدِ بْنِ خَالِدٍ الطَّيَالِسِيِّ عَنْ عَلِيِّ بْنِ أَبِي حَمْزَةَ عَنْ أَبِي بَصِيرٍ عَنْ أَبِي عَبْدِ اللَّهِ ( عليه السلام ) قَالَ مَنْ لَبِسَ السَّرَاوِيلَ مِنْ قُعُودٍ وُقِيَ وَجَعَ الْخَاصِرَةِ .
7. Abu Ali al-Ash‘ariy has narrated from certain persons of his people from Muhammad ibn Khalid al-Tayalisy from Ali ibn abu Hamzah from abu Basir who have said the following: “Abu ‘Abd Allah (a.s.), has said, ‘If one wears a loincloth in a sitting position, he remains safe from lower back pain.’”
Source: Shaykh Muḥammad b. Yaʿqūb al-Kulaynī