Skandapurana 16.207.32

16.207.32

brahmacāriṇi yajñe ca yatau śilpini dīkṣite ..
yajñe vivāhe satre ca sūtakaṃ na kadācana .. 32 ..

For a celibate student, at a sacrifice, for an ascetic, for an artisan, for an initiated person, / at a sacrificial rite, at a marriage, and at a long sacrificial session, there is never ritual impurity. // 32