ISB ~ Mark 2 v14

Levi:Also called “Matthew” (Mt 9:9). He abandoned his occupation to follow Jesus and was later named an apostle (3:18).

the tax office:The Pharisees despised tax collectors as “sinners” (2:15) for several reasons. (1) Collecting revenue in Galilee involved frequent contact with Gentiles. By Pharisaic standards, this meant that collectors were exposed to the ritual defilement of the pagans. (2) Since taxes were collected for the unwelcome Romans, who ruled Palestine, collectors were branded as traitors to Israel’s hope for national independence. (3) Collectors were sometimes guilty of extortion, exacting personal commissions above the required tax amount.