Charles Ellicott Commentary Judges 15:3

"And Samson said unto them, This time shall I be blameless in regard of the Philistines, when I do them a mischief." — Judges 15:3 (ASV)

Concerning them. —There is no reason for this rendering. It should be to them. The Vulgate has cui, and the Septuagint "to them," or "to him."

Now —i.e., This time. He means that his second act of vengeance will at least have more excuse than his assault on the Askelonites.

More blameless than the Philistines. —Rather, innocent as regards the Philistines. The words are somewhat obscure. Ewald renders them—

"This time I am blameless concerning the Philistines,
If it's evil I am thinking of doing to them."