Shatapatha Brahmana 11.1.3.6

11.1.3.6

sa yatpaurṇamāseneṣṭvā athānyaddhaviranunirvapatyāmāvāsyeneṣṭvāthānyaddhaviranunirvapati dviṣantaṃ ha sa bhrātṛvyaṃ pratyucrayate'tha yaḥ paurṇamāsīṃ yajata āmāvāsyenāmāvāsyāmasapatnā haivāsyānupabādhā śrīrbhavati

When, after performing the Full-moon sacrifice, he afterwards prepares another oblation; and when, after performing the New-moon sacrifice, he afterwards prepares another oblation, he rises and defies his malicious enemy; and, indeed, unassailed and undisturbed is the prosperity of him who at full moon performs the Full-moon sacrifice, and at new moon the New-moon sacrifice.