Here’s how a parenthetical statement can provide interesting insights about the provenance of a Biblical book. Mk 15:21 says, “And they compelled a passerby, Simon of Cyrene, who was coming in from the country, the father of Alexander and Rufus, to carry his cross.”
Identifying Simon as the father of Alexander and Rufus only makes sense if Mark’s audience personally knew Alexander and Rufus. Mark added “the father of Alexander and Rufus” to help his audience identify the particular Simon who helped Jesus carry His cross.
Thinking to Believe 