Deuteronomy 4:9-10

9Only take heed to thyself, and keep thy soul diligently, lest thou shouldest forget the things which thy eyes have seen, and lest they depart from thy heart all the days of thy life: but teach them to thy sons, and thy sons’ sons;

10Especially the day that thou stoodest before the LORD thy God in Horeb, when the LORD said to me, Gather the people to me, and I will make them hear my words, that they may learn to fear me all the days that they shall live upon the earth, and that they may teach their children.