Translation:

188. Say: "I have no power over any good or harm to myself except as Allah willeth. If I had knowledge of the unseen I should have multiplied all good and no evil should have touched me I am but a warner and a bringer of glad tidings to those who have faith."

Notes (Tafseer)

1161. A warner to all, and a bringer of glad tidings to those who have faith, because they will profit by the glad tidings. As every one is invited to faith, the glad tidings are offered to all, but they are not necessarily accepted by all.