Translation:

50. Say: "If I am astray I only stray to the loss of my own soul: but if I receive guidance it is because of the inspiration of my Lord to me: it is He Who hears all things and is (ever) near."

Notes (Tafseer)

3862. If it could possibly be supposed that the Prophet was a self-deceived visionary, it would affect him only, and could not fail to appear in his personality. But in fact he was steady in his constancy and Faith, and he not only went from strength to strength, but won the enduring and whole-hearted love and devotion of his nearest and dearest and of those who most came into contact with him. How was this possible, unless he had the Truth and the inspiration of Allah behind him? This is the fifth and last argument in this passage.