Agni is the two the sacred hearth and also the deity of that fireplace who transmits oblations to another deities. As a result, this mantra is recited though invoking the deity Agni in the shape of fire as witness into the vow. Neda Gould, director with the mindfulness program at https://directoryforrank.com/listings13299525/a-secret-weapon-for-beej-mantra