Hiranyakeshigrihyasutra 1.3.9.18

1.3.9.18

ānaḍuhe śakṛtpiṇḍe saṃyamya keśaśmaśrulomanakhāni \ idamahamamuṣyāmuṣyāyaṇasya pāpmānamavagūhāmi \ iti goṣṭha udumbare darbhastambe vā nikhanati yosya rātirbhavati \18\

A person who is kindly disposed (towards the student), gathers the hair, the beard, the hair of the body, and the nails (that have been cut off), in a lump of bull's dung, and buries (that lump of dung) in a cow-stable, or near an Udumbara tree, or in a clump of Darbha grass, with (the words), 'Thus I hide the sin of N.N., who belongs to the Gotra N.N.'