Soora no. 80 proves the truthfulness of Prophet Mohammed, and that he was not infallible; the prophet may make some mistakes by the will of God to declare that he was not infallible.
This is a nice recitation of this valuable soora no. 80:

Here is the meaning of this great soora no. 80:
Soora 80
(In the name of God, Most Gracious, Most Merciful)
[Abdullah son of Ummi Maktoom was one of the companions of God’s messenger, and he was blind; the Prophet sent him to one of Quraish tribesmen to invite him to convert and embrace the Islam religion.
So when Abdullah came and talked to him, he disdained to comply with a blind and poor man, so he frowned and turned away from him and did not listen to his words.
Then Abdullah returned and told the Prophet about that, and said: “If you yourself go to him, he may comply with your words and yield to you.”
Then that man regretted afterwards about his turning away, and came to the Prophet and converted.
Therefore, these ayat were revealed:]

1. One [of the Quraish tribesmen] scowled [at the blind man] and turned in aversion [away from believing.]
2. When a blind man [: Abdullah, the son of Ummi Maktuom] came [inviting] him [to believe.]
3. But you [Mohammed] know not that [had you yourself gone to invite him to believe] he might [have converted and] become purified [from the disbelief and association!]
4. Or he might have received admonition [of the Quran], and the admonition would then have profited him!
5. Then as for him who is disdainfully indifferent [to the Quran, and who gets away from it],
6. To him you [Mohammed] attend [in order to rehearse to him some of the Quran revelations.]
7. Yet nothing [of his punishment will fall] on you, if he does not purify himself [from the association.]
8. Whereas he who came to you, walking with determination [and converted],
9. While he feared [God's punishment, if he persists on his association.]
10. Him you [Mohammed] do ignore!
11. By no means e ; for the [Quran revelations] are indeed an admonition.
12. So let whosoever likes [to have admonition], receive the admonition [of the Quran.]
13. In honorable books.
14. Lifted up [to heaven], and kept pure [from any association with God.]
15. By the hands of the envoys.
16. Who are honorable [before God] and pious.)
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11 e Do not do such a thing: to target him who is disdainfully indifferent to the Quran, and ignore the one who has a sincere desire in the faith.

More explanation of these ayat and the rest of this soora is in the link:
Last edited by Torch light; Sep 5th, 2018 at 04:29 PM..