Apastambadharmasutra 2.1.2.9

2.1.2.9

avagāhanam apām upasparśane saṃbhāṣāyāṃ brāhmaṇasaṃbhāṣā darśane jyotiṣāṃ darśanam // ( = K 9+10 )

(The penance) for touching him is to bathe, submerging the whole body; for speaking to him to speak to a Brâhmana; for looking at him to look at the lights (of heaven).