Translation:

52. Here is a Message for mankind: let them take warning therefrom and let them know that He is (no other than) One Allah: let men of understanding take heed.

Notes (Tafseer)

1931. Here is another aspect of the Truth of Unity. Allah being One, all justice is of one standard, for Truth is one, and we see it as one as soon as the scales of phenomenal diversity fall from our eyes. The one true Reality then emerges. Blessed are those who treasured this Truth in their souls already in their life of probation.