“Therefore the showers have been withheld.” 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).
“latter rain.” This is the rain that falls at the end of the rainy season which brings the grain to maturity. Without it, the grain will not mature and there will be no harvest. See commentary on James 5:7.
“forehead of a prostitute.” A descriptive metaphor for bold, shameless, committed to sin. The people of Judah were committed to their sin and had no desire to repent.