Ver. 16-20. We heard of the call of these four apostles before, in Matthew. See Poole on "Matthew 4:18", and following verses to Matthew 4:22, upon which may be found whatsoever is necessary for the explication of these verses, (having nothing new in them), as also the reconciling of what John saith, 1 Thessalonians 1:40, about the calling of Andrew and Simon, to what these two evangelists say about it.
Related Commentaries of Mark 1:16
Mark 1:16
16 Now as he walked by the sea of Galilee, he saw Simon and Andrew his brother casting a net into the sea: for they were fishers.