Garudapurana 1.213.39

1.213.39

saṃmṛjyāṅguṣṭhamūlena tribhirāsyamupaspṛśet /
aṅguṣṭhena pradeśinyā ghrāṇaṃ paścādanantaram //

Having wiped [it] with the base of the thumb, one should touch the mouth with three [fingers]; / immediately afterward, the nose with the thumb and the forefinger;