Translation:

17. "That We might try them by that (means) but if any turns away from the remembrance of his Lord He will cause him to undergo a severe Penalty.

Notes (Tafseer)

5741. To remember Allah is to realise His presence, acknowledge Iiis Goodness, and accept His guidance. If we fail to do so, by deliberately turning away, He will withdraw His Grace, and that will be a severe Penalty indeed.