Varahashrautasutra 2.2.3.9

2.2.3.9

gāvīdhukaṃ caruṃ payasi śṛtamupadadhāti tasyāmeveṣṭakāyām̐ yo rudro'psu yo'gnau ya oṣadhīṣu yo rudro viśvā bhuvanāviveśa tasmai rudrāya namo'stu devāya - iti

On that very brick, he places a caru of gavīdhukā boiled in milk, with ‘Whatever Rudra is in the waters, in the fire, who is in the plants, whatever Rudra has entered all beings, to that divine Rudra be homage’.