Surah 40:55
"So be patient! Surely the promise of God is true. Ask forgiveness for your sin, and glorify your Lord with praise in the evening and the morning."
– Ask forgiveness for your sin
The Quran instructs the messenger to ask forgiveness for his sin (dhanb). This is one of several verses (also 47.19; 48.2) that question the Islamic doctrine that all prophets are sinless or immune (ma‘ṣūm). See a discussion of these verses at 48.2.
- from The Quran with Christian Commentary: A Guide to Understanding the Scripture of Islam