Shatapatha Brahmana 9.1.1.27

9.1.1.27

athāvatānānjuhoti | etadvā enāndevā etenānnena prītvāthaiṣāmetairavatānairdhanūṃṣyavātanvaṃstathaivainānayametadetenānnena prītvāthaiṣāmetairavatānairdhanūṃṣyavatanoti na hyavatatena dhanuṣā kaṃ cana hinasti

He then offers (the libations of the) 'unstringing'-formulas. For at that time the gods, having gratified those (Rudras) by that food, unstrung their bows by means of these 'unstringing'-formulas; and in like manner this (Sacrificer), having gratified them by that food, now unstrings their bows by means of these 'unstringing'-formulas; for with an unstrung bow one injures no one.