Isaiah 63: 15
Look down from heaven, and behold from the habitation of Thy holiness and of Thy glory: where is Thy zeal and Thy strength, the sounding of Thy bowels and of Thy mercies toward me? are they restrained?
Israel, deep into captivity, finally repents as a nation. They begin this prayer, which takes us to the end of the chapter, asking God to reveal Himself to them again as in days of old. They recognize that He is in heaven; that He is holy. They seek His power and His zeal to protect His people.
“The sounding of Thy bowels” is a phrase that could compare to “the sighing of the heart.” It was believed that emotion was seated in the organs of the chest, and the word bowels was included in that concept. It seems strange to us, but it was a common expression of emotion. The main thing here is that the people felt that God was holding back His mercy and compassion from His people.