ChU 4.10.4
अथ हाग्नयः समूदिरे । तप्तो ब्रह्मचारी कुशलं नः पर्यचारीत् । हन्तास्मै प्रब्रवामेति तस्मै होचुः । प्राणो ब्रह्म कं ब्रह्म खं ब्रह्मेति
atha hāgnayaḥ samūdire | tapto brahmacārī kuśalaṃ naḥ paryacārīt | hantāsmai prabravāmeti tasmai hocuḥ | prāṇo brahma kaṃ brahma khaṃ brahmeti
Devanagari rendered by HREEM from the edition's roman (IAST) text; the IAST is the edition's own.
Thereupon the fires said among themselves: 'This student, who is quite exhausted, has carefully tended us. Well, let us teach him.' They said to him:
Translated by F. Max Müller