大般涅槃經疏 18.18

18.18

「云何念僧」下，即第三念。舊亦為二：先明別體事和僧；「不可覩見」下，次明一體理和僧。今明不爾。文云「受正直法」，三教非直，唯有圓僧是正直法。

From "How does one recollect the Saṅgha?" downward is the third recollection. Ancient commentators also made it into two: first, explaining the conventional harmony saṅgha of distinct essence; from "Invisible" downward, next explaining the principle harmony saṅgha of identical essence. Now we explain that it is not so. The text says: "Receives the straight and upright Dharma." The three teachings are not straight; only the saṅgha of the Perfect [teaching] is the straight and upright Dharma.