Deuteronomy 21:2-4

New American Standard Bible

² then your elders and your judges shall go out and measure the distance to the cities which are around the one who was killed. ³ And it shall be that the city which is nearest to the person killed, that is, that the elders of that city shall take a heifer of the herd that has not been worked ^[a]and has not pulled in a yoke; ⁴ and the elders of that city shall bring the heifer down to a valley with running water, which has not been plowed or sown, and they shall break the heifer’s neck there in the valley.