And it shall come to pass in that day, I will hear, saith the LORD, I will hear the heavens, and they shall hear the earth; I will hear, saith the Lord - The sentence is repeated, to show how fully the thing was determined by the Almighty, and how implicitly they might depend on the Divine promise.
I will hear the heavens - The visible heavens, the atmosphere, where vapours are collected. The clouds, when they wish to deposit their fertilizing showers upon the earth.
They shall hear the earth - When it seems to supplicate for rain.