Shatapatha Brahmana 14.3.1.22

14.3.1.22

athaitadrajjusandānam upayamanyāmādhāya paścātprācīmāsādayatyudaramevāsminnetaddadhāti tadabhitaḥ pinvane āṇḍāvevāsminnetaddadhātyāṇḍābhyāṃ hi vṛṣā pinvate paścātsthūṇāmayūkhamūrū evāsminnetaddadhāti paścādrauhiṇakapāle jānunī evāsminnetaddadhāti te yadekakapāle bhavata ekakapāle iva hīme jānunī paścāddhṛṣṭī pādāvevāsminnetaddadhāti pādābhyāṃ hi dhṛṣṭam praharatyuttarataḥ kharau pracaraṇīyau taddhi tayorāyatanaṃ dakṣiṇato mārjālīyaṃ taddhi tasyāyatanam

He then puts the cords and halter on the supporting-tray, and places (the latter) behind (the navel) with its point towards the east: a belly he thus gives to it. On the two sides thereof the two milking-bowls (pinvana): two testicles he thereby gives to it, for by means of his testicles the male overflows (pinv). Behind (them he places) the post and peg: whereby he gives two thighs to it; behind (them) the two Rauhina-plates, whereby he gives two knees to it; and as to their being single plates, it is because these knees consist, as it were, of single plates (bones). Behind (them) the two poking-sticks (dhrishti), whereby he gives two feet to it, for with the feet one strikes out boldly (dhrishtam). On the left side the two mounds used in the performance,. for there is their place of rest; on the right side the Mârgâlîya, for there is its place of rest.