俱舍論記 8.19

8.19

「彼界二從至能伏色想」者，說一切有部答。從勝定生，故彼二強。由定伏色，故說定勝。或定伏色，故不依色，但依此二。

"These two in that realm arise from... capable of subduing the notion of form" is the answer of the Sarvāstivāda. Because they arise from superior absorption, those two are strong. Because the absorption subdues form, the absorption is said to be superior. Or, because the absorption subdues form, they do not rely on form, but only rely on these two.