Deuteronomy 4:12

9 Only take heed to thyself, and keep thy soul diligently, lest thou forget the things which thine eyes saw, and lest they depart from thy heart all the days of thy life; but make them known unto thy children and thy children`s children;

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

11 And ye came near and stood under the mountain; and the mountain burned with fire unto the heart of heaven, with darkness, cloud, and thick darkness.

12 And Jehovah spake unto you out of the midst of the fire: ye heard the voice of words, but ye saw no form; only [ye heard] a voice.

13 And he declared unto you his covenant, which he commanded you to perform, even the ten commandments; and he wrote them upon two tables of stone.

14 And Jehovah commanded me at that time to teach you statutes and ordinances, that ye might do them in the land whither ye go over to possess it.

15 Take ye therefore good heed unto yourselves; for ye saw no manner of form on the day that Jehovah spake unto you in Horeb out of the midst of the fire.