Numbers 2:2

By his own standard, or ensign, by that to which he is allotted by the following order. It is manifest that there were four great standards or ensigns, which here follow, distinguished by their colours or figures, or otherwise; also that there were other particular ensigns belonging to each of their father's houses or families, as is here said. Far off; partly out of reverence to God and his worship, and the portion allotted to it, and partly for caution, lest their vicinity to it might tempt them to make too near approaches to it. It is supposed they were at two thousand cubits distance from it, which was the space between the people and the ark, Joshua 3:4, and it is not improbable, because the Levites encamped round about it between them and the tabernacle.