'Companion' in the Bible

Going out the next day, Moses noticed two Hebrew men fighting right in front of him. He told the one who was at fault, "Why did you strike your companion?"

And he said unto them, Thus saith the LORD God of Israel, Put every man his sword by his side, and go in and out from gate to gate throughout the camp, and slay every man his brother, and every man his companion, and every man his neighbour.