Israel depends heavily on rain in order to grow its crops, as it does not have an independent body of water which can provide sufficient irrigation. Water can be the source of great blessing, but at the wrong times, too much or too little water can also be a curse. In this verse, Hashem promises that if the Children of Israel follow His commandments and do what He asks of them, He will bless them with the right amount of water at the right times, in order to provide an abundance of crops. In Hebrew, this rain is called gishmay b’racha (גשמי ברכה), ‘rain of blessing’ (Ezekiel 34:26).
Source: Israel in the News