But Ehud made him a dagger which had two edges, of a cubit length; and he did gird it under his raiment upon his right thigh.

Wesley's Notes

3:16 A cubit length - Long enough for his design, and not too long for concealment. His right thigh - Which was most convenient both for the use of his left hand, and for avoiding suspicion.

Jamieson-Fausset-Brown Bible Commentary

16. Ehud made him a dagger . and he did gird it . upon his right thigh-The sword was usually worn on the left side; so that Ehud's was the more likely to escape detection.

Matthew Henry's Concise Commentary

3:12-30 When Israel sins again, God raises up a new oppressor. The Israelites did ill, and the Moabites did worse; yet because God punishes the sins of his own people in this world, Israel is weakened, and Moab strengthened against them. If lesser troubles do not do the work, God will send greater. When Israel prays again, God raises up Ehud. As a judge, or minister of Divine justice, Ehud put to death Eglon, the king of Moab, and thus executed the judgments of God upon him as an enemy to God and Israel. But the law of being subject to principalities and powers in all things lawful, is the rule of our conduct. No such commissions are now given; to pretend to them is to blaspheme God. Notice Ehud's address to Eglon. What message from God but a message of vengeance can a proud rebel expect? Such a message is contained in the word of God; his ministers are boldly to declare it, without fearing the frown, or respecting the persons of sinners. But, blessed be God, they have to deliver a message of mercy and of free salvation; the message of vengeance belongs only to those who neglect the offers of grace. The consequence of this victory was, that the land had rest eighty years. It was a great while for the land to rest; yet what is that to the saints' everlasting rest in the heavenly Canaan.