Augustine of Hippo
Catena Aurea · Matthäusevangelium 22
But when the Pharisees had heard that he had put the Sadducees to silence, they were gathered together. Then one of them, which was a Lawyer, asked him a question, tempting him, and saying, Master, which is the great commandment in the Law? Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself. On these two commandments hang all the Law and the Prophets.
(de Doctr. Christ. i. 30.) It is clear that every man is to be regarded as a neighbour, because evil is to be done to no man. Further, if every one to whom we are bound to shew service of mercy, (vid. Rom. 13:10.) or who is bound to shew it to us, be rightly called our neighbour, it is manifest that in this precept are comprehended the holy Angels who perform for us those services of which we may read in Scripture. Whence also our Lord Himself would be called our neighbour; for it was Himself whom He represents as the good Samaritan, who gave succour to the man who was left half-dead by the way.