Jaiminīya Upaniṣad Brāhmaṇa 3.9.4

3.9.4

atha ya enam etad dīkṣayanti tad dvitīyam mriyate
vapanti keśaśmaśrūṇi
nikṛntanti nakhān
pratyañjanty aṅgāni
pratyacaty aṅgulīḥ
apavṛto 'paveṣṭita āste
na juhoti
na yajate
na yoṣitaṃ carati
amānuṣīṃ vācaṃ vadati
mṛtasya vāvaiṣa tadā rūpam bhavati /

"Then, when they consecrate him, then he dies for the second time.
They shave his hair and beard;
they cut his nails;
they anoint his limbs;
he bends in his fingers;
he sits uncovered and wrapped up;
he does not offer oblation;
he does not sacrifice;
he does not approach a woman;
he speaks non-human speech;
he is then indeed in the form of a dead man.