Translation:

38. There can be no difficulty to the Prophet in what Allah has indicated to him as a duty. It was the practice (approved) of Allah amongst those of old that have passed away and the command of Allah is a decree determined.

Notes (Tafseer)

3727. See n. 3724 above.

3728. The next clause is parenthetical. These words then connect on with verse 39. Among the people of the Book there was no taboo about adopted sons, as there was in Pagan Arabia.

3729. Allah's ordering of the world is always full of wisdom. Even our unhappiness and misery may actually have a great meaning for ourselves or others or both. If our first Plan seems to fail, we must not murmur and repine, but retrieve the position by adopting a course which appears to be the best possible in the light of our duties as indicated by Allah. For Allah's Plan is framed on universal principles that cannot be altered by human action.