A.T. Robertson Commentary John 5:16

"And for this cause the Jews persecuted Jesus, because he did these things on the sabbath." — John 5:16 (ASV)

Persecute (εδιωκον). Inchoative imperfect, "began to persecute" and kept it up. They took this occasion as one excuse (δια τουτο, because of this). They disliked Jesus when here first (2:18) and were suspicious of his popularity (4:1). Now they have cause for an open breach.

Because he did (οτ εποιε). Imperfect active, not just this one act, but he was becoming a regular Sabbath-breaker. The Pharisees will watch his conduct on the Sabbath henceforth (3:2).