成唯識論述記 6.25

6.25

述曰：作意之性能警心、心所，令趣自境。此若無者，心則不起。不起故心現行無，非無種子。

The Commentary states: The nature of attention can alert the mind and mental factors, causing them to turn toward their own sphere. If this were absent, the mind would not arise. Because it would not arise, the actual functioning (samudācāra) of the mind would not exist, not that its seeds (bīja) would not exist.