Yoga Sūtra Chapter Two verse 51

बाह्याभ्यन्तर विषयाक्षेपी चतुर्थः ॥५१॥

bāhya-ābhyantara-viṣaya-ākṣepī caturthaḥ ||51||

The fourth transcends the external and internal as an object.

bāhya - externalābhyantara - internalviṣaya - objectākṣepīn - transcendscaturtha - fourth