俱舍論記 14.157

14.157

「是故歸依至為方便門」者，結。是故歸依，普於一切八眾所受諸律儀處，為前方便道引之門，由能發戒永脫眾苦。若不歸依，戒不發故。

Regarding the conclusion, "Therefore taking refuge [...] serves as the preparatory gateway": Therefore, taking refuge universally serves as the preparatory pathway and introductory gate for all the disciplines received by the eight classes [of disciples], because it is able to give rise to the precepts and eternally liberate one from all suffering. If one does not take refuge, the precepts will not arise.