“a left-handed man.” The Hebrew is an idiom, a man who was limited (or “bound”) in his right hand. It likely is the standard idiom for “left-handed,” although there is some possibility that Ehud was somehow crippled in his right hand. The idiom is clearly used in Judges 20:16. Ehud was a “Benjamite” (from “son of my right hand”) who was impeded in his right hand. Ehud is the only man in the Bible who is named who is left-handed.
“The children of Israel sent by his hand a tribute.” In this section of Scripture we see how the work of God can do what the work of humans cannot do. The Israelites sent a tribute to Eglon, but that would not have ended their subjugation, if anything it would have extended it. However, God used that human effort to give an opportunity to Ehud, who had the spirit of God, to open a relationship with the Moabite king, Eglon, and eventually get close enough to him to kill him and begin the deliverance of Israel.