'Take Heed' in the Bible

That Jehovah may establish his word which he spake concerning me, saying, If thy children take heed to their way, to walk before me in truth with all their heart and with all their soul, there shall not fail thee (said he) a man on the throne of Israel.

Now therefore, O Jehovah, the 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 on the throne of Israel, if only thy children take heed to their way, to walk before me as thou hast walked before me.