Yet the words in which Peter and those in which Satan are rebuked, are not, as is commonly thought, the same; to Peter it is said, “Get thee behind me, Satan;” that is, follow me, thou that art contrary to my will; to the Devil it is said, “Go thy way, Satan,” understanding not ‘behind me,’ but ‘into everlasting fire.’
He said therefore to Peter, “Get thee behind me,” as to one who through ignorance was ceasing to walk after Christ. And He called him Satan, as one, who through ignorance had somewhat contrary to God. But he is blessed to whom Christ turns, even though He turn in order to rebuke him. But why said He to Peter, “Thou art an offence unto me, when in the Psalm it is said, Great peace have they that love thy law, and there is no offence to them?” [Ps 119:165] It must be answered, that not only is Jesus not offended, but neither is any man who is perfect in the love of God; and yet he who does or speaks any thing of the nature of an offence, may be an offence even to one who is incapable of being offended. Or he may hold every disciple that sinneth as an offence, as Paul speaks, “Who is offended, and I burn not?” [2 Cor 11:29]
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).