'Have Mercy' in the Bible

Then the angel of the LORD replied, "O LORD of hosts, how long will you not have mercy on Jerusalem and on the cities of Judah, against which you have had indignation these seventy years?"

"I will strengthen the house of Judah, and I will save the house of Joseph, and I will bring them back; for I have mercy on them; and they will be as though I had not cast them off: for I am the LORD their God, and I will hear them.