Śatapatha Brāhmaṇa ("of a hundred paths") 13.8.4.5

13.8.4.5

yatrodakam bhavati tatsnānti sumitriyā na āpa oṣadhayaḥ santvityañjalināpa upācati vajro vā āpo vajreṇaivaitanmitradheyaṃ kurute durmitriyāstasmai santu yo'smāndveṣṭi yaṃ caparāsiñcettenaiva tam parābhāvayati

They bathe at any place where there is water. With (Vâg. S. XXXV, 12), 'May the waters and plants be friendly unto us!' he takes water with his joined hands,--for water is a thunderbolt: with the thunderbolt he thus makes friendship,--and with, 'Unfriendly may they be unto him who hateth us, and whom we hate!' he throws it in the direction in which he who is hateful to him may be, and thereby overthrows him.