Śatapatha Brāhmaṇa ("of a hundred paths") 9.1.2.4

9.1.2.4

agnītpariṣiñcati | agnireṣa yadāgnīdhro no vā ātmātmānaṃ hinastyahiṃsāyā aśmano 'dhyaśmano hyāpaḥ prabhavanti nikakṣānnikakṣāddhyāpaḥ prabhavanti dakṣiṇānnikakṣāddakṣiṇāddhi nikakṣādāpaḥ prabhavanti

For safety from injury it is the Agnîdh who sprinkles, for the Agnîdh is the same as Agni, and no one injures his own self. From a stone (he sprinkles), for from the rock water springs forth;--from the arm-pit, for from the arm-pit water springs forth; from the right arm-pit, for from the right arm-pit water springs forth.