That I will give you the rain of your land in his due season, the first rain and the latter rain, that thou mayest gather in thy corn, and thy wine, and thine oil. (Deuteronomy 11:14)
This was the autumn rain, which fell at the time of planting the winter crops, to sprout the seed and give it a good start before the cold of winter set in. It fell in the eighth month, our late autumn (see Ezra 10:9, 13). In a land dependent on rain the seed would not sprout unless the rain fell in its season (Lev. 26:4).
The latter rain.
This fell in the spring before the harvest, during our months of March and early April, and brought the crop to full maturity (see Jer. 5:24; Joel 2:23). In his reply to the false charges of Eliphaz, Job speaks figuratively of the importance of the latter rain (Job 29:23). Solomon uses it as an illustration of favors bestowed by a king (Prov. 16:15), and Hosea, of revival and reformation (Hosea 6:2, 3). The tragedy that resulted from a failure of the latter rain is described by Jeremiah in his first message to the backslidden church of his day (Jer. 3:3; cf. Amos 4:7; see on Joel 2:23).