Śatapatha Brāhmaṇa ("of a hundred paths") 3.1.2.8

3.1.2.8

pracidyodapātre prāsyati | tūṣṇīmevottaraṃ godānamabhyunatti tūṣṇīṃ darbhataruṇakamantardadhāti tūṣṇīṃ kṣureṇābhinidhāya pracidyodapātre prāsyati

Having cut off (part of the stalk and hair), he throws it into the vessel of water. Silently he moistens the left whisker; silently he lays the stalk of grass on it; and having silently applied the razor thereto and cut through (it and the hair), he throws them into the vessel of water.