Mahāpadesa - The Great Reasons - VinMv.6.40.1 (Vin1.6.40.1)

Now at that time uncertainty arose in the sāmaṇas with regard to several things: "What does the fortunate one allow? What is not allowed?" So they relayed the issue to the fortunate One:
(The Buddha) "Meditators, whatever I have not forbidden, saying, 'This is not a proper thing for you to do,' if it fits in with what is not a proper thing for you to do, if it goes against what is a proper thing, then, this too is not a proper thing for you to do.

"Whatever I have not forbidden, saying, 'This is not a proper thing for you to do,' if it fits in with what is a proper thing for you to do, if it goes against what is not a proper thing, then, this too is a proper thing for you to do.

"And whatever I have not allowed, saying, 'This is a proper thing for you to do,' if it fits in with what is not a proper thing for you to do, if it goes against what is a proper thing, then, this too is not a proper thing for you to do.

"And whatever I have not allowed, saying, 'This is a proper thing for you to do,' if it fits in with what is a proper thing for you to do, if it goes against what is not a proper thing, then, this is a proper thing for you to do."