SB 3.8.20

tamasy apāre vidurātma-sargaṁ
 vicinvato ’bhūt sumahāṁs tri-ṇemiḥ
yo deha-bhājāṁ bhayam īrayāṇaḥ
 parikṣiṇoty āyur ajasya hetiḥ
Word for word: 
tamasi apāre — because of an ignorant way of searching; vidura — O Vidura; ātma-sargam — the cause of his creation; vicinvataḥ — while contemplating; abhūt — it so became; su-mahān — very great; tri-nemiḥ — time of three dimensions; yaḥ — which; deha-bhājām — of the embodied; bhayam — fearfulness; īrayāṇaḥ — generating; parikṣiṇoti — diminishing the one hundred years; āyuḥ — duration of life; ajasya — of the self-born; hetiḥ — the wheel of eternal time.
Translation: 
O Vidura, while searching in that way about his existence, Brahmā reached his ultimate time, which is the eternal wheel in the hand of Viṣṇu and which generates fear in the mind of the living entity like the fear of death.