瑜伽師地論略纂 2.41

2.41

「八福生」者，謂欲界粟散王為一，臣為二，加六欲天為八。不同古解：欲界除臣，而取輪王。輪王為九。不動善為十，謂色無色善及無漏善。

"Eight births of merit": these refer to a petty king in the desire realm as one, ministers as the second, which added to the six desire-realm heavens make eight. This differs from the ancient explanation: in the desire realm, ministers were excluded and the wheel-turning king was taken. The wheel-turning king would be the ninth. Unmoving wholesome states are the tenth, referring to wholesome states of the form and formless realms and uncontaminated wholesome states.