Gopalacampu 1.17.16

1.17.16

dharmo' yaṃ laukikas tāta yadyapi syād athāpy asau |
yuktatvād api cāmnāyād āmnāyaja iveṣyate || ya indro devatātra syāt parjanyaḥ sa tu sarvavit |
tasyārcanaṃ kulāyātam asmākaṃ ketanaṃ matam || [anuṣṭubh]

"Even though this duty may be customary, dear son, nevertheless, because it is reasonable and also from sacred tradition, it is accepted as if born of sacred tradition. / Indra, who is the deity here, is all-knowing Parjanya; his worship, come down through the family, is considered our celebration."