俱舍論頌疏論本 7.46

7.46

無色善生九者，謂無色善心能生九心。言九心者，於十二心中除欲界二善及無覆，除色界一所謂無覆。

"Wholesome of the formless gives rise to nine": this means that a wholesome mind of the formless [realm] can give rise to nine minds. Saying "nine minds" means that among the twelve minds, the two wholesome [minds] and the unimpeded of the desire realm are excluded, and one of the form realm—namely, the unimpeded—is excluded.