Did you not, O our God, drive out the inhabitants of this land before your people Israel, and give it forever to the descendants of your friend Abraham? They have lived in it, and in it have built you a sanctuary for your name, saying, "If disaster comes upon us, the sword, judgment, or pestilence, or famine, we will stand before this house, and before you, for your name is in this house, and cry to you in our distress, and you will hear and save." See Now the people of Ammon, Moab, and Mount Seir, whom you would not let Israel invade when they came from the land of Egypt, and whom they avoided and did not destroy—they reward us by coming to drive us out of your possession that you have given us to inherit. (2 Chronicles 20:7-11, NRSV)
Art not thou our God, who didst drive out the inhabitants of this land before thy people Israel, and gavest it to the seed of Abraham thy friend for ever? And they dwelt therein, and have built thee a sanctuary therein for thy name, saying, If, when evil cometh upon us, as the sword, judgment, or pestilence, or famine, we stand before this house, and in thy presence, (for thy name is in this house,) and cry unto thee in our affliction, then thou wilt hear and help. And Now behold, the children of Ammon and Moab and mount Seir, whom thou wouldest not let Israel invade, when they came out of the land of Egypt, but they turned from them, and destroyed them not; Behold, I say, how they reward us, to come to cast us out of thy possession, which thou hast given us to inherit. (2 Chronicles 20:7-11, KJV)
Jehoshaphat appeals to God to rescue Judah from the invaders who are trying to take back the land of Judah. He reminds God that he gave this land to Abraham's descendants forever and that Israel had built him this really nice Temple for just an occasion like this—to pray for deliverance. The king makes a pretty savvy argument here: don't do this for us, do it for yourself, since your house is here.