'Fail' in the Bible

Now therefore, O LORD God of Israel, keep with thy servant David my father that which thou hast promised him, saying, There shall not fail thee a man in my sight to sit upon the throne of Israel; yet so that thy children take heed to their way to walk in my law, as thou hast walked before me.

Then will I stablish the throne of thy kingdom, according as I have covenanted with David thy father, saying, There shall not fail thee a man to be ruler in Israel.