Vijnana Bhairava Tantra
वायुद्वयस्य सम्घट्टाद् अन्तर् वा बहिरन्ततः । योगी समत्वविज्ञानसमुद्गमनभाजनम् ॥ ६४ ॥
From the fusion of both vayus (prana and apana) inside or outside (the body), the yogi attains equilibrium and becomes fit for the proper manifestation of consciousness.
english translation
vAyudvayasya samghaTTAd antar vA bahirantataH । yogI samatvavijJAnasamudgamanabhAjanam ॥ 64 ॥
hk transliteration by Sanscript