The tribe of Gad marched, along with that of Simeon, under
   the standard of Reuben; and it seems, on that account, to
   have been introduced in this order.  The other tribes also,
   are here classed together according to their encampments, and
   the order of their subsequent march.

  2:14,15  26:15-18  Ge 30:10,11  46:16  49:19