四分律行事鈔資持記 1.99

1.99

示堪能中，初句牒其能者。必下，示其博贍。上二句明學通三藏，下二句明解總六師。吾祖律師即其人也。聖人出現，為物垂範，謂之教跡。雖言通三藏，而別指律宗，故云斯也。

Under 'showing capability', the first line takes up the one who is capable. From 'Must' downward, it reveals his broad erudition. The upper two lines clarify that his learning penetrates the three piṭakas; the lower two lines clarify that his understanding encompasses the six masters. Our Patriarchal Master, the Vinaya master, is indeed that person. When a sage appears in the world to leave a model for living beings, it is called 'traces of teaching'. Although it says 'penetrating the three piṭakas', it specifically refers to the Vinaya school, hence it says 'this'.