The “latter rain” is that which falls in March or April just before the harvest. The “cloud” which brings it, immediately screening people from the scorching sun, and bringing plenty and blessing, is a fit type of the highest favor.
SDA Bible Commentary (limited)
Volume 1-7
15. The latter rain.. This statement gives a contrast to v.14. The clouds that bring the latter rain swell the grain that was sown in the time of the former rain in the autumn of the previous year (see Job 29:23; Jer. 5:24). Similarly, the protection of the king’s favor provides an environment that encourages progress (see Ps. 72:6).