Manava Dharmashastra 5.104

5.104

na vipraṃ sveṣu tiṣṭhatsu mṛtaṃ śūdreṇa nāyayet
asvargyā hy āhutiḥ sā syāc chūdrasaṃsparśadūṣitā //

Let him not allow a dead Brahmana to be carried out by a Sudra, while men of the same caste are at hand; for that burnt-offering which is defiled by a Sudra's touch is detrimental to (the deceased's passage to) heaven.