Praise be to Allah.
Firstly: the use of the word “sin” in the question is a grave mistake, because sin (khatee’ah, pl. khataayaa) is impossible in the case of the Messengers. It is more correct to say mistakes, because a mistake may be made unintentionally, which is not the case with sins.
Secondly: with regard to sins, the Messengers, including Muhammad (peace and blessings of Allah be upon him), never committed any sin intentionally as an act of disobedience towards Allah after receiving their Mission (risaalah). This is according to the consensus of the Muslims. They were protected from major sins (kabaa’ir) but not from minor sins (saghaa’ir).
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said:
The view that the Prophets were protected from major sins (kabaa’ir) but not from minor sins (saghaa’ir) is the view of the majority of the scholars of Islam and all the sects… It is also the view of the majority of the scholars of tafseer and hadeeth, and of the fuqahaa’. Nothing was reported from any of the Salaf, Imaams, Sahaabah, Taabi’een or the successive generation that does not agree with this view.
(Majmaa’ al-Fatawaa, 4/319).
This question was posed to the Standing Committee on this topic:
Some people, including the heretics, say that the Prophets and Messengers could make mistakes, i.e., they could make mistakes like all other people. They say that the first mistake ever made was when the son of Adam, Qaabeel, killed Haabeel… and when the two angels came to Dawood, he listened to the first and did not listen to what the second had to say… and the story of Yoonus when the big fish swallowed him; and the story of the Messenger with Zayd ibn Haarithah, they say that he concealed something which he should have declared openly; and with his Sahaabah, he told them, “You know better about your worldly affairs,” and they say that this is because he made a mistake in this regard; and what happened with the blind man, which is referred to in the aayah (interpretation of the meaning), “(The Prophet) frowned and turned away, because there came to him the blind man…” [‘Abasa 80:1-2]. Could the Prophets and Messengers really make mistakes? How can we respond to these sinners [who say these things]?
Yes, the Prophets and Messengers made mistakes, but Allah did not approve of their mistakes; rather, He pointed out their mistakes as a Mercy to them and their ummahs, and He forgave their mistakes and accepted their repentance as a Grace and Mercy, for Allah is Oft-Forgiving, Most Merciful. This will be clear to anyone who checks out the aayaat of the Qur’aan in which the matters raised in the question are discussed… With regard to the sons of Aadam, even though they were not Prophets… Allah explained how evil was the deed which he did to his brother…
(Fatawaa al-Lajnah al-Daa’imah, no. 6290, 3/194).
Thirdly: before they were given their Mission (risaalah), the scholars have said that it is possible that they may have committed some minor sins, but they were protected from committing major sins such as zinaa, drinking wine, etc.
But after they received their Mission, the correct view is that they may have committed some minor mistakes but this was not approved of and they were rebuked.
Shaykh al-Islam [Ibn Taymiyah] said:
Most of the reports from the majority of scholars state that they were not infallible with regard to minor mistakes, but they were not allowed to persist in them; they do not say that this could never happen at all. The first suggestion that they were completely infallible came from the Raafidis, who say that they are so infallible that they could never make any mistake even by way of forgetfulness and misunderstanding.
(Majmoo’ al-Fatawaa, 4/320).
They are infallible with regard to conveying the Message from Allah, may He be exalted.
Shaykh al-Islam [Ibn Taymiyah] (may Allah have mercy on him) said:
The aayaat which indicate the Prophethood of the Prophets also indicate that they are infallible with regard to the conveying of the Message from Allah; so what they say can only be true. This is the meaning of Prophethood, which implies that Allah tells the Prophet something of the Unseen and he tells it to the people. And the Messenger is commanded to call the people to Allah and to convey the message of his Lord.
(Majmoo’ al-Fatawaa, 18/7)
Fourthly: mistakes which are committed unintentionally are of two types:
With regard to worldly matters: this happened to the Messenger of Allah (peace and blessings of Allah be upon him). With regard to agriculture, medicine, carpentry, etc., he was like all other people. Allah did not tell us that he was sent to us as a businessman or a farmer or a carpenter or a doctor. His mistakes in these fields are quite natural and do not impact on his Message at all.
It was reported that Raafi’ ibn Khudayj said: The Prophet (peace and blessings of Allah be upon him) came to Madeenah, and they were pollinating the date-palms. He said, “What are you doing?” They said, “We always used to pollinate them.” He said, “Perhaps if you do not do that, it will be better.” So they did not do it, and the harvest was lacking. They mentioned that to him, and he said, “I am only a human being like you. If I tell you to do something with regard to religion, then follow it, but if I tell you to do something based on my own opinion, I am only a human being.”
(narrated by Muslim, 2361).
We note that the Messenger (peace and blessings of Allah be upon him) made a mistake in this worldly matter, because he was like all other human beings, but with regard to matters of religion he did not make mistakes.
With regard to unintentional mistakes concerning matters of religion:
The most correct view among the scholars is that the way this happened with regard to the Prophet (peace and blessings of Allah be upon him) is that he might do something which is OK but it was not the more appropriate choice.
He was sometimes faced with issues concerning which there was no shar’i text on which he could base his decision, so he sought to make ijtihaad based on his own opinion, just as any Muslim scholar may make ijtihaad, and if he makes the right decision, he will be given two rewards, and if he makes the wrong decision, he will still be given one reward. This is what the Prophet (peace and blessings of Allah be upon him) said: “If the judge makes ijtihaad and gets it right, he will have two rewards, and if he makes ijtihaad and gets it wrong, he will have one reward.”
(Narrated by al-Bukhaari, 6919; Muslim, 1716, from the hadeeth of Abu Hurayrah).
This also happened to him concerning the prisoners of Badr.
Anas said: the Messenger of Allah (peace and blessings of Allah be upon him) consulted the people concerning the prisoners who had been captured on the day of Badr. He said, “Allah has given you power over them.” ‘Umar ibn al-Khattaab stood up and said, “O Messenger of Allah, strike their necks [execute them]!” The Prophet (peace and blessings of Allah be upon him) turned away from him. Then the Messenger of Allah (peace and blessings of Allah be upon him) came back and said, “O people, Allah has given you power over them and they were your brothers.” ‘Umar stood up and said, “O Messenger of Allah, strike their necks [execute them]!” The Prophet (peace and blessings of Allah be upon him) turned away from him. Then the Prophet (peace and blessings of Allah be upon him) came back and said something similar to the people. Abu Bakr stood up and said, “O Messenger of Allah, why don’t you forgive them and accept payment of ransom from them?” The worried expression left the face of the Messenger of Allah (peace and blessings of Allah be upon him), and he forgave them and accepted their payment of ransom. Then Allah revealed the words (interpretation of the meaning):
“It is not for a Prophet that he should have prisoners of war (and free them with ransom) until he had made a great slaughter (among his enemies) in the land. You desire the good of this world (i.e. the money of ransom for freeing the captives), but Allah desires (for you) the Hereafter. And Allah is All-Mighty, All-Wise” [al-Anfaal 8:67]
Narrated by Ahmad (13143).
We may note that in this case, the Messenger of Allah (peace and blessings of Allah be upon him) did not have any clear text so he made ijtihaad and consulted his companions, and he made a mistake in deciding what was the best thing to do.
Cases like this are few in the Sunnah. We have to believe that the Messengers and Prophets are infallible, and we know that they did not disobey Allah. We should also beware of the words of those who want to cast aspersions on his conveying of the Message by referring to the fact that he (peace and blessings of Allah be upon him) made some mistakes with regard to earthly matters. There is a huge difference between the former and the latter. We should also beware of those misguided people who say that some of the rulings of sharee’ah which the Prophet (peace and blessings of Allah be upon him) told us about are his own personal ijtihaad which could be right or wrong. What would these misguided people say in response to the words of Allah (interpretation of the meaning): “Nor does he speak of his own desire. It is only an Inspiration that is inspired” [al-Najm 53:3]? We ask Allah to protect us from confusion and misguidance, And Allah knows best.