Śatapatha Brāhmaṇa ("of a hundred paths") 5.2.1.16

5.2.1.16

athainamūṣapuṭairanūdasyanti | paśavo vā ūṣā annaṃ vai paśavo 'nnaṃ vā eṣa ujjayati yo vājapeyena yajate 'nnapeyaṃ ha vai nāmaitadyadvājapeyaṃ tadyadevaitadannamudajaiṣīttenaivaitadetāṃ gatiṃ gatvā saṃspṛśate tadātmankurute tasmādenamūṣapuṭairanūdasyanti

They throw up to him bags of salt; for salt means cattle, and cattle is food; and he who offers the Vâgapeya wins food, for vâga-peya is the same as anna-peya: thus whatever food he thereby has gained, therewith now that he has gone to the supreme goal, he puts himself in contact, and makes it his own,--therefore they throw bags of salt up to him.