Mahabharata 13.18.26

13.18.26

tulyaṃ mama sahasraṃ tu sutānāṃ brahmavādinām |
āyuścaiva saputrasya saṃvatsaraśatāyutam || 26 ||

"Garga said,--'O son of Pandu, gratified with me in consequence of mental sacrifice which I had performed, the great God bestowed upon me, on the banks of the sacred stream Saraswati, that wonderful science, viz., the knowledge of Time with its four and sixty branches. He also, bestowed upon me, a thousand sons, all possessed of equal merit and fully conversant with the Vedas. Through his grace, their periods of life as also that of mine have become extended to ten millions of years.'"