Shatapatha Brahmana 1.1.4.12

1.1.4.12

tāni vā etāni | catvāri vāca ehīti brāhmaṇasyāgahyādraveti vaiśyasya ca rājanyabandhoścādhāveti śūdrasya sa yadeva brāhmaṇasya tadāhaitaddhi yajñiyatamametadu ha vai vācaḥ śāntataṃ yadehīti tasmādehītyeva brūyāt

Now there are four different forms of this call, viz. 'come hither (ehi)!' in the case of a Brâhman; 'approach (âgahi)!' and 'hasten hither (âdrava)!' in the case of a Vaisya and a member of the military caste (râganyabandhu); and 'run hither (âdhâva)!' in that of a Sûdra. On this occasion he uses the call that belongs to a Brâhman, because that one is best adapted for a sacrifice, and is besides the most gentle:. let him therefore say, 'come hither (ehi)!'