'Take Heed' in the Bible

That the LORD may continue his word which he spoke 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.

Therefore now, LORD God of Israel, keep with thy servant David my father that which thou didst promise him, saying, There shall not fail thee a man in my sight to sit on the throne of Israel; provided thy children take heed to their way, that they walk before me as thou hast walked before me.