Readers of Mark 1:14 and Matt. 4:12–17 might question our evangelist’s account that the Baptist and Jesus were thus baptized simultaneously. So John states that this occurred prior to the Baptist’s imprisonment. Therefore, this is the reason for the statement and not the self-evident fact that the Baptist’s work ceased when he was cast into prison. That also is why John has the article: had been cast “into the prison,” referring his readers to this famous prison and the Baptist’s confinement there, which they knew of the other evangelists.