तद्यदृक्तो रिष्येद्भूः स्वाहेति गार्हपत्ये जुहुयादृचामेव तद्रसेनर्चां वीर्येणर्चां यज्ञस्य विरिष्टँ संदधाति ॥ ४ ॥
In plain words
If the sacrifice suffers a flaw on the side of the Ṛc hymns, one should offer an oblation in the Gārhapatya fire saying, 'Bhūḥ, svāhā!' Through the very essence and potency of the Ṛcs, he heals the broken parts of the sacrifice.
Close to the Sanskrit
If that sacrifice should suffer a flaw from the Ṛc side, one should offer an oblation in the Gārhapatya fire with 'Bhūḥ svāhā!'. By the essence alone of the Ṛcs, by the potency of the Ṛcs, he heals the broken part of the sacrifice related to the Ṛcs.