Translation:

48. Say: "Verily my Lord doth cast the (mantle of) Truth (over His servants) He that has full knowledge of (all) that is hidden."

Notes (Tafseer)

3860. Allah's Truth is so vast that no man in this life can compass the whole of it. But Allah in His mercy selects His servants on whom it is cast like a mantle. They see enough to be able to teach their fellow men. It is through that mantle-that mission received from Allah-that a messenger can speak with authority to men, and this is his third argument.