SB 12.8.14

tasyaivaṁ yuñjataś cittaṁ
 mahā-yogena yoginaḥ
vyatīyāya mahān kālo
 manvantara-ṣaḍ-ātmakaḥ
Word for word: 
tasya — he; evam — thus; yuñjataḥ — while fixing; cittam — his mind; mahā-yogena — by powerful practice of yoga; yoginaḥ — the mystic sage; vyatīyāya — passed by; mahān — a great; kālaḥ — period of time; manu-antara — lifetimes of Manu; ṣaṭ — six; ātmakaḥ — consisting of.
Translation: 
While the mystic sage thus concentrated his mind by powerful yoga practice, the tremendous period of six lifetimes of Manu passed by.