Why did pure Jews look down on and detest the Samaritans?
The Samaritans at this point in time were considered half-breed Jews. They had lost their pure character as Jews, so the pure Jew looked down upon and detested them. This loss of pure Jewish identity caused their rejection by the pure Jew.
Les teaches that in Matthew 10, when Jesus sent forth the twelve, He commanded them not to go into the way of the Gentiles or into any city of the Samaritans. The Samaritans at that point in time were half-breed Jews. They had lost their pure character as Jews, and consequently were looked down upon and detested by the pure Jew. Jesus would later in His ministry still go to the city of Samaria.