UtshovBhagavad Gita 4.29
अपाने जुह्वति प्राण प्राणेऽपानं तथाऽपरे।
प्राणापानगती रुद्ध्वा प्राणायामपरायणाः।।4.29।।
Apane juhvati prana pranepanam tathapare
Pranapanagati ruddhva pranayamaparayanah
Simple meaning, written by AIOne offers his breath to another and receives the breath back; by stopping this exchange of breath they become devoted to pranayama.