大方廣佛華嚴經隨疏演義鈔 61.24

61.24

疏「若分二樂則有十一」者，《俱舍》云「此實事十一，初二樂輕安，內淨即信根，喜即是喜受。」謂初二禪樂是輕安樂，第三禪樂是樂受樂，故成十一。

Regarding the commentary's phrase "if one distinguishes the two kinds of pleasure, there are eleven": the Kośa says: "These real entities are eleven: / The pleasure of the first two is pliancy; / Internal purity is the faculty of faith; / Joy is precisely the feeling of joy." This means that the pleasure of the first and second dhyānas is the pleasure of pliancy (praśrabdhi), while the pleasure of the third dhyāna is the pleasure of pleasurable feeling; hence they make eleven.