'Take Heed' in the Bible

"Now therefore, 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 in my law as you have walked before me.'

Now therefore let the fear of the LORD be on you. Take heed and do it: for there is no iniquity with the LORD our God, nor respect of persons, nor taking of bribes."