Mantra 1

अथ यां चतुर्थीं जुहुयात्तां जुहुयात्समानाय स्वाहेति समानस्तृप्यति ॥ ५.२२.१ ॥

In plain words

The fourth offering that he makes, let him make with the words "To the even breath, svāhā." Then the even breath is satisfied.