妙法蓮華經玄贊 10.5

10.5

釋名者，「隨」者順從之名，「喜」者忻悅之稱，身心順從深生忻悅，以此為因生功德果。此品廣明，故名彼品。隨所聞思修皆生隨喜心，論經從初，但說聞故。

Explaining the title: 'Sui' (following) is the name for compliance; 'xi' (rejoicing) is the term for joy and delight. Complying in body and mind and profoundly generating joy and delight serves as the cause that produces the fruit of merit. Because this chapter extensively clarifies it, the chapter is named after it. One generates a mind of rejoicing in accordance with whatever is heard, contemplated, or cultivated; the treatise and sūtra follow the beginning, speaking only of hearing.