Śatapatha Brāhmaṇa ("of a hundred paths") 3.3.3.10

3.3.3.10

atha rājānamādatte | mitro na ehi sumitradha iti śivo naḥ śānta ehītyevaitadāha taṃ yajamānasya dakṣiṇa ūrau pratyuhya vāso nidadhātīndrasyorumāviśa dakṣiṇamityeṣa vā atrendro bhavati yadyajamānastasmādāhendrasyorumāviśa dakṣiṇamityuśannuśantamiti priyaḥ priyamityevaitadāha syonaḥ syonamiti śivaḥ śivamityevaitadāha

He takes the king, with the text (Vâg. S. IV, 27), 'Come to us, a friend, bestowing good friends!' whereby he means to say, 'Come to us, as a kind and propitious one!' Having pushed back the garment on the sacrificer's right thigh, he lays him (Soma) down thereon, with the text, 'Seat thee on Indra's right thigh,'--for he, the sacrificer, is at present Indra: therefore he says, 'Seat thee on Indra's right thigh;'--'willing on the willing,' whereby he means to say, 'beloved on the beloved one;'--'tender on the tender!' whereby he means to say, 'propitious on the propitious one.'