'Take Heed' in the Bible

That the LORD may establish his word which he spoke concerning me, saying, 'If your 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 you,' he said, 'a man on the throne of Israel.'

Now therefore, may the LORD, the God of Israel, keep with your servant David my father that which you have promised him, saying, 'There shall not fail you a man in my sight to sit on the throne of Israel, if only your children take heed to their way, to walk before me as you have walked before me.'