Apastambadharmasutra 2.2.5.16

2.2.5.16

upākaraṇād ā-utsarjanād#1 adhyāpayitur niyamaḥ /#2 lomasaṃharaṇaṃ māṃsaṃ śrāddhaṃ maithunam iti ca [varjayet / ( = K 15, 1: upākaraṇādyā-utsarjanād , 2: om. / )

The restrictions (to be kept) by the teacher from the beginning of the course of teaching to its end are, to avoid cutting the hair on the body, partaking of meat or of oblations to the Manes, and connection (with a woman).