俱舍論記 11.86

11.86

「如是所說至故使之然」者，此下第二便顯餘義。就中，一明六天行婬、二明諸天初生、三明欲生樂生。此即第一明六天行婬。

"As to what has been said... this makes it so": below this is the second main part, which clarifies other matters. Within this: first, explaining the sexual intercourse of the devas of the six [desire heavens]; second, explaining the initial birth of the devas; third, explaining the productions of desire and the productions of pleasure. This is the first, explaining the sexual intercourse of the devas of the six [desire heavens].