俱舍論記 5.47

5.47

「彼雖曾習至無未來修」者，彼無想定雖復過去曾習，以無心故，要起大加行方便修得，故初得時唯得現在。如初受得別解脫戒，亦唯成現。得此定已，第二念等乃至未捨以來，亦成就過去。出已乃至未捨已來，唯成過去，以無心故無未來修。

"Although they previously practiced it... there is no future cultivation," although that non-conceptual concentration was previously practiced in the past, because it is mindless, it must be obtained by cultivation through great preparatory application and expedients; therefore, when initially obtained, one obtains only the present moment. Just as when initially receiving and obtaining the prātimokṣa vows, one also only accomplishes the present. Having obtained this concentration, from the second moment onward until it has not yet been abandoned, one also possesses the past. After emerging, until it has not yet been abandoned, one possesses only the past. Because it is mindless, there is no future cultivation.