For instance, a man may go into the forest with his neighbor to cut wood, and as he swings his ax to fell a tree, the head may fly off and hit his neighbor and kill him. That man may flee to one of these cities and save his life.
NIV
As when a man goes into the wood with his neighbor to hew wood, and his hand strikes with the ax to cut down the tree, and the head slips off the handle and lights on his neighbor and kills him--he may flee to one of those cities and live
AMP
As when a man goeth into the wood with his neighbour to hew wood, and his hand fetcheth a stroke with the axe to cut down the tree, and the head slippeth from the helve, and lighteth upon his neighbour, that he die; he shall flee unto one of those cities, and live:
KJV