Śatapatha Brāhmaṇa ("of a hundred paths") 4.6.9.12

4.6.9.12

yaduttarasya havirdhānasya | jaghanyāyāṃ kūbaryāmaganma jyotiramṛtā abhūmeti jyotirvā ete bhavantyamṛtā bhavanti ye sattramāsate divam pṛthivyā adhyāruhāmeti divaṃ vā ete pṛthivyā adhyārohanti ye sattramāsate 'vidāma devāniti vindanti hi devāntsvarjyotiriti trirnidhanamupāvayanti svarhyete jyotirhyete bhavanti tadyadevaitasya sāmno rūpaṃ tadevaite bhavanti ye sattramāsate

That is, on the hinder shaft of the northern cart. 'We have gone to the light, we have become immortal,'--for they who sit through a sacrificial session become indeed the light, they become immortal;--'to the sky have we ascended from the earth,'--for they who sit through a sacrificial session indeed ascend from the earth to the sky;--'we have attained to the gods,'--for they indeed attain to the gods;--'to heaven, to the light!' thrice they repeat the finale; for they indeed become (partakers of) heaven and bliss. Thus, whatever the nature of his Sâman is, that they come to be who sit through a sacrificial session.