Whoever is out in an open field and touches the body of someone who was killed by a sword, or a dead body, or someone's bones, or a grave, he is to be considered unclean for seven days.

all of a sudden the donkey saw the angel of the LORD standing in the way, with an unsheathed sword in his hand! The donkey turned off the road and went into an open field. Balaam started beating the donkey in order to turn her back to the road,

So Balak took him to the field of Zophim, and from there to the top of Mount Pisgah, where he built seven altars and then offered a bull and a ram on each altar.