The phrase "came on" means that Yahweh's Spirit influenced Samson. In this case, he made him very strong. Alternate translation: "made Samson very strong" or "made Samson very powerful" (See: [[rc://en/ta/man/translate/figs-idiom]])
These were from the plunder he had taken from Ashkelon. Alternate translation: "the sets of clothing that he had taken" (See: [[rc://en/ta/man/translate/figs-explicit]])