Mark 1:16

1:16 As he went along the Sea of Galilee, he saw Simon and Andrew, Simon’s brother, casting a net into the sea (for they were fishermen). ¹ 

Mark 2:14

2:14 As he went along, he saw Levi, the son of Alphaeus, sitting at the tax booth. ²  “Follow me,” he said to him. And he got up and followed him.

¹ sn This is a parenthetical comment by the author.

² tn While “tax office” is sometimes given as a translation for τελώνιον (telwnion, so L&N 57.183), this could give the modern reader a false impression of an indoor office with all its associated furnishings.