Deuteronomy 19:3-5

Young's Literal Translation

³ Thou dost prepare for thee the way, and hast divided into three parts the border of thy land which Jehovah thy God doth cause thee to inherit, and it hath been for the fleeing thither of every man-slayer.

⁴ `And this [is] the matter of the man-slayer who fleeth thither, and hath lived: He who smiteth his neighbour unknowingly, and is not hating him heretofore,

⁵ even he who cometh in with his neighbour into a forest to hew wood, and his hand hath driven with an axe to cut the tree, and the iron hath slipped from the wood, and hath met his neighbour, and he hath died -- he doth flee unto one of these cities, and hath lived,