Commentaire sur Les Psaumes 48:4

He is known as a stronghold When He will dwell therein in the future, they will say this [will call Him thus].

God is in its palaces – The palaces of other cities are strongly built and elevated to take shelter in. The strength of the palaces of Jerusalem is better than these because God is known in them and He is a stronghold to all who seek shelter in Him, as it is written “The name of the Lord is a tower of strength; the righteous runs into it and is strengthened.” (Proverbs 18:10)