Are there theological explanations for why God would condition his divine intervention and mercy on intercessory prayer?

Ezekiel 22:29-31 (ESV): > 29 The people of the land have practiced extortion and committed robbery. They have oppressed the poor and needy, and have extorted from the sojourner without justice. 30 **And I sought for a man among them who should build up the wall and stand in the breach before me for the land, that I should not destroy it, but I found none**. 31 Therefore I have poured out my indignation upon them. I have consumed them with the fire of my wrath. I have returned their way upon their heads, declares the Lord God.” Why did God seek for someone to intercede for the land? Why is intercessory prayer so important to God? Why does God condition his divine intervention and mercy on human intercession (or lack thereof)? I'm interested in theological explanations, with no preference for any particular denomination or school of thought, although citations of reputable sources would be a plus and certainly appreciated.