John Chrysostom
Otherwise; The Lord desires to teach that men ought to seek aid from above, but at the same time to contribute what lays in their power; wherefore when He had said, Ask, seek, and knock, He proceeds to teach openly that men should be at pains for themselves, adding, Whatsoever ye would &c.
He says not, All things whatsoever, simply, but All things therefore, as though He should say, If ye will be heard, besides those things which I have now said to you, do this also. And He said not, Whatsoever you would have done for you by God, do that for your neighbour; lest you should say, But how can I? but He says, Whatsoever you would have done to you by your fellow-servant, do that also to your neighbour.
Whence what we ought to do is clear, as in our own cases we all know what is proper, and so we cannot take refuge in our ignorance.
Otherwise; He had above commanded us in order to sanctify our prayers that men should not judge those who sin against them. Then breaking the thread of his discourse He had introduced various other matters, wherefore now when He returns to the command with which He had begun, He says, All things whatsoever ye would, &c. That is; I not only command that ye judge not, but All things whatsoever ye would that men should do unto you, do ye unto them; and then you will be able to pray so as to obtain.
For whatsoever ever the Law and the Prophets contain up and down through the whole Scriptures, is embraced in this one compendious precept, as the innumerable branches of a tree spring from one root.