Mosiah 19:8

"And now the king was not so much concerned about his people as he was about his own life; nevertheless, Gideon did spare his life."

This king received mercy from Gideon because he talked about the safety of his people. The king used this trickery to save himself. In reality he did not care about his people at all! He just did not want to die. This is how Satan works, too. He does not care for anyone but himself and will use you for his own benefit.