Albert Barnes Commentary Joshua 9:4

"they also did work wilily, and went and made as if they had been ambassadors, and took old sacks upon their asses, and wine-skins, old and rent and bound up," — Joshua 9:4 (ASV)

They did work wilily - literally, “they also,” or “they too, did work, and so on.” The “also” serves, apparently, to connect the stratagem of the Gibeonites with that employed by the Israelites before Ai. It hints that the Gibeonites resolved to meet craft with craft.

Rent and bound up - that is, the wine skins were torn and roughly repaired by tying up the edges of the tear. The more thorough and careful way, hardly feasible in a hasty journey, would have been to insert a patch.