What About Moses’ Heart?

Moses/Moshe knew the people of Egypt, perhaps more than any other living Hebrew. As prince he had power over countless servants, knew their families, their firstborns. Moshe also knows that Pharaoh will not send away the people before the final plague. He knows that so many innocent people, people he was familiar with and even family with, would die. He even knows that the Egyptians have begun to look with favor and graciousness upon the Hebrew slaves (Exodus 11:3). How could he in good conscience announce the last plague? What happened to Moshe’s heart?