Mal 2 Verse 7 gives a clear indication: “The lips of a priest are the ones that should keep knowledge, and the law is what people should seek from his mouth; for he is the messenger of Jehovah of armies. ”
يعطي العدد ٧ سببا واضحا :‏ « لأن شفتَي الكاهن تحفظان معرفة ومن فمه يطلبون الشريعة لأنه رسول رب الجنود » .‏