Khadiragrihyasutra 1.4.2

1.4.2

brāhmaṇakule 'gnimupasamādhāya paścādagnerlohitaṃ carmānaḍuhamuttaraloma prāggrīvamāstīrya vāgyatāmupaveśayet / 2

In a Brâhmana's house he should establish the (nuptial) fire, should spread out to the west of the fire a red bull's hide with the hair outside and with the neck to the east, and should make her, who has to keep silence, sit down (thereon).