Mahabharata — Anushasana Parva, Shloka 18
अत्रेः तपोबलप्रकाशः तथा च्यवनस्य सोमाधिकारः
Atri’s Illumination by Tapas; Cyavana and Soma-Entitlement
मृतकस्य त्रिरात्रे यः समुद्दिष्टे समश्षुते । सप्त त्रिषवर्णं स्नात्वा पूतो भवति ब्राह्मण:
mṛtakasya trirātre yaḥ samuddiṣṭe samaśnute | sapta triṣavarṇaṃ snātvā pūto bhavati brāhmaṇaḥ ||
毗湿摩说道：若一位婆罗门在处于丧秽（死亡不净）的家中，连续三夜食用为亡者所设的供食，则当以七日之期，于每日三次交时——清晨、正午与黄昏——沐浴自净，便得清净。此教诫彰显法（dharma）对仪式清净的重视，并指示在触及死亡之不净后，依经典所定之法复归净洁。
भीष्य उवाच
Educational Q&A
Contact with death-related impurity through eating food offered in that context creates ritual defilement, and dharma prescribes a specific purification: thrice-daily bathing for seven days, emphasizing disciplined restoration of purity rather than denial of the transgression.
In Anuśāsana Parva’s dharma-instruction, Bhīṣma lays down a rule about a brāhmaṇa who repeatedly eats in a household under death-impurity and states the required purificatory practice to regain ritual fitness.