And unto the Jews I became as a Jew, that I might gain the Jews; to them that are under the law, as under the law, that I might gain them that are under the law;
All Commentaries on 1 Corinthians 9:20 Go To 1 Corinthians 9
Augustine of Hippo
AD 430
A person who nurses a sick man becomes, in a sense, sick himself, not by pretending to have a fever but by thinking sympathetically how he would like to be treated if he were sick himself. Letter , To Jerome.