Kathakagrihyasutra 37.23

37.23

ekakarmaṇi tantre uttareṇāgniṃ pratyetya pratyānīyāgneḥ paścāddarbheṣu vinihitacaraṇau vadhūvarau kṛtvā 'sā tvamasi' iti varaṃ gururvācayati |
sā nāma ṛgāsīt, amo nāma sāma, sā ca amaśca sāma ṛk ca gītiścetyarthaḥ | evaṃ sāmaśabdasya vyutpattiḥ | ṛksāmarūpāvāvāmiti vibhajya varaḥ pradarśayati - he vadhu tvaṃ sā ṛgasi bhavasi, amo'hamasmi ahamamaḥ sāma bhavāmi| sā tvaṃ sā tvaṃ bhavasi, amo'hamamo'haṃ bhavāmīti dviruktyā ṛksāmarūpatvaṃ draḍhayati | tā ehi vivahāvahai tau dvāvāvāṃ he vadhu ehyāgaccha vivahāvahai vivāhaṃ kurvaḥ | kimartham | puṃse putrāya kartave, kartave iti tumarthe bhāve tavenpratyayaḥ, puṃse putrāyeti subvyatyayaḥ, pumāṃsaṃ putraṃ kartum | tathā rāyo dhanasya poṣāya puṣṭaye, suprajāstvāya śobhanaprajālābhāya, suvīryāya suvīryaṃ karmasvojasvitā tadartham |