Śatapatha Brāhmaṇa ("of a hundred paths") 14.2.2.11

14.2.2.11

yamāya tvāṅgirasvate pitṛmate svāheti ayam vai yamo yo'yam pavate tasmā evainaṃ juhoti tasmādāha yamāya tvetyaṅgirasvate pitṛmata iti yajñasya śīrṣacinnasya [raso vyakṣaratsa] pitṝ!nagacattrayā vai pitarastānevaitadanvābhajati

[Vâg. S. XXXVIII, 9,] 'To Yama, accompanied by the Aṅgiras and the Fathers,--thee, hail!'--Yama indeed is he who blows here: it is to him he thus offers it, and therefore he says, 'To Yama--thee;' and as to his saying, 'accompanied by the Aṅgiras and the Fathers,'--when the sacrifice had its head cut off, its life-sap flowed away, and went to the Fathers,--the Fathers being three in number: thus it is to these he thereby allows a share along (with Yama).