Shatapatha Brahmana 9.5.2.3

9.5.2.3

tadyadetenopatiṣṭhate | yadevāsyātra vidvānvāvidvāti vā recayati na vābhyāpayati tadevāsyaitena sarvamāptam bhavati yadasya kiṃ cānāptaṃ ya u tasyāmanuṣṭubhyṛci kāmo 'traiva tamāpnotyathā etasmādevaitatkarmaṇo rakṣāṃsi nāṣṭrā apahanti no hainamanuvyāhāriṇa stṛṇvate tasmādapyevaṃvitkāmam parasmā agniṃ cinuyādīśvaro ha śreyānbhavitoḥ

Thus, when he reverently stands by (the altar) with this (hymn), everything is thereby made good for him that, knowing or unknowing, he either does in excess, or does not carry to the end, in this building of the altar--in short, whatever was not secured for him. And whatever wish there is in that anushtubh verse, that he secures even now; and, moreover, he thereby keeps off the fiends, the Rakshas, from this sacred work, and they do not wreck him, whilst uttering imprecations. Wherefore one who knows this may readily build a fire-altar even for an enemy, for he is able to gain the better of him.