"Then saith the woman of Samaria unto him, How is it that thou, being a Jew, asketh drink of me, which am a woman of Samaria? for the Jews have no dealings with the Samaritans" (John 4:9). The Savior’s request struck this woman with surprise. She knew the extreme dislike which Jews cherished towards Samaritans. It was accounted a sin for them to have any friendly intercourse with that people. The general tendency of this antipathy may be judged from the following extracts from the Jewish rabbins by Bishop Lightfoot:—It is prohibited to eat the bread, and to drink the wine of the Samaritan." "If any one receives a Samaritan into his house, and ministers to him, he will cause his children to be carried into captivity." "He who eats the bread of a Samaritan, is as if he ate swine’s flesh."
Source: Arthur Pink, Exposition of the Gospel of John