These are they that went over Jordan in the first month, when it had overflown all his banks; and they put to flight all them of the valleys, both toward the east, and toward the west. (1 Chronicles 12:15)
Nisan (or Abib), the first month of the religious year, is approximately our late March to late April. This month came at the close of the rainy season (see Vol. II, pp. 108, 110). These heroes did not wait till summer, when the Jordan was shallow, before venturing out on their exploits, but crossed the river at the most difficult and perilous season, when it was in full flood.