So since you saw no form of any kind on the day the LORD spoke to you out of the fire at Horeb, be careful
KJV
Take ye therefore good heed unto yourselves; for ye saw no manner of similitude on the day [that] the LORD spake unto you in Horeb out of the midst of the fire:
ASV
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;