The first commandment
Though we use the phrase, “The Ten Commandments”, the Decalogue is ten Words or Principles. The first says that there is One God and He brought us from bondage to freedom.
After proclaiming His existence, why does He speak of His deeds?
Because the crucial thing is not just that He is, but that He has a relationship with the people of Israel and He acts within history. His deeds prove His power and confirm His nature. They show what He is capable of doing and indicate why He does it.
Without this information, we might have found it hard to be certain of His existence. As the Torah says in Parashat Ki Tissa (Ex. 33:19-20), we cannot see Him, but we can see His deeds: He is not visible or tangible, but He is powerful.
