“I will give the rain of your land in its season.” One of the great lessons of the Bible is that the behavior of people affects the land that they live on. This lesson is throughout the Old Testament (cp. Deut. 11:13-17; 28:1, 12, 15, 22-25, 38-40; Lev. 18:24-25; Ps. 107:33-34; Jer. 3:2-3; 12:4; 23:10; Amos 4:6-10). (See commentary on Lev. 18:25).
“former and latter rain.” There was one rainy season in Israel, and it usually started in mid to late October and ended in April. The rains at the start of the season got the planting going, and were called the “former” rains. The rains at the end of the wet season allowed the grain to come to maturity and were called the “latter” rains. For more on the rainy season and the former and latter rain, see commentary on James 5:7.