In the following hadiths, Muhammad admits he is a liar when it suits him and advises that it is acceptable for Muslims to do likewise:
We were in the company of Abu Musa Al-Ash'ari and there were friendly relations between us and this tribe of Jarm. Abu Musa was presented with a dish containing chicken. Among the people there was sitting a red-faced man who did not come near the food. Abu Musa said (to him), "Come on (and eat), for I have seen Allah's Apostle eating of it (i.e. chicken)." He said, "I have seen it eating something (dirty) and since then I have disliked it, and have taken an oath that I shall not eat it ' Abu Musa said, "Come on, I will tell you (or narrate to you). Once I went to Allah s Apostle with a group of Al-Ash'ariyin, and met him while he was angry, distributing some camels of Rakat. We asked for mounts but he took an oath that he would not give us any mounts, and added, 'I have nothing to mount you on' In the meantime some camels of booty were brought to Allah's Apostle and he asked twice, 'Where are Al-Ash'ariyin?" So he gave us five white camels with big humps. We stayed for a short while (after we had covered a little distance), and then I said to my companions, "Allah's Apostle has forgotten his oath. By Allah, if we do not remind Allah's Apostle of his oath, we will never be successful." So we returned to the Prophet and said, "O Allah's Apostle! We asked you for mounts, but you took an oath that you would not give us any mounts; we think that you have forgotten your oath.' He said, 'It is Allah Who has given you mounts. By Allah, and Allah willing, if I take an oath and later find something else better than that. then I do what is better and expiate my oath.'
Narrated 'Abdur-Rahman bin Samura:
The Prophet said, "O 'Abdur-Rahman! Do not seek to be a ruler, for if you are given authority on your demand then you will be held responsible for it, but if you are given it without asking (for it), then you will be helped (by Allah) in it. If you ever take an oath to do something and later on you find that something else is better, then you should expiate your oath and do what is better.
Abu Musa al-Ash'ari reported: I came to Allah's Apostle (may peace be upon him) along with a group of Ash'arites requesting to give us a mount. He (the Holy Prophet) said: By Allah, I cannot provide you with a mount, and there is nothing with me which I should give you as a ride. He (the narrator) said: We stayed there as long as Allah willed. Then there were brought to him (to the Holy Prophet) camels. He (the Holy Prophet) then ordered to give us three white humped camels, We started and said (or some of us said to the others): Allah will not bless us. We came to Allah's Messenger (may peace be upon him) begging him to provide us with riding camels. He swore that he could not provide us with a mount, but later on he provided us with that. They (some of the Prophet's Companions) came and informed him about this (rankling of theirs), whereupon he said: It was not I who provided you with a mount, but Allah has provided you with that. So far as I am concerned, by Allah, if He so wills, I would not swear, but if, later on, I would see better than it, I (would break the vow) and expiate it and do that which is better.
Abu Huraira reported: A person sat late in the night with Allah's Apostle (may peace be upon him), and then came to his family and found that his children had gone to sleep. His wife brought food for him. but he took an oath that he would not eat because of his children (having gone to sleep without food) He then gave precedence (of breaking the vow and then expiating it) and ate the food He then came to Allah s Messenger (may peace be upon him) and made mention of that to him, whereupon Allah's Messenger (may peace he upon him) said: He who took an oath and (later on) found something better than that should do that, and expiate for (breaking) his vow.
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: He who took an oath and then found another thing better than (this) should expiate for the oath (broken) by him and do (the better thing).
Abu Huraira reported Allah's Messenger (may peace be upon him) as saying: He who took an oath and (later on) found another thing better than that, he should do that which is better, and expiate for the vow (broken by him).
This hadith is narrated on the authority of Suhail with the same chain of transmitters (with these words): "He should expiate for (breaking) the vow and do that which is better."
'Adi reported Allah's Messenger (may peace be upon him) as saying: When anyone amongst you takes an oath, but he finds (something) better than that he should expiate (the breaking of the oath), and do that which is better.
Abd al-Rahman b. Samura reported that Allah's Messenger (may peace be upon him) said to me: Abd al-Rahman b. Samura, don't ask for authority for if it is granted to you for asking for it, you would be commissioned for it (without having the support of Allah), but if you are granted it without your asking for it. You would be helped (by Allah) in it. And when you take an oath and find something else better than that, expiate for (breaking) your oath, and do that which is better. This hadith has also been transmitted on the authority of Ibn Farrukh.
Apologists often claim lying in Islam is restricted to its use in war, but in the following hadiths, Muhammad permits a Muslim to lie in order to kill Ka'b ibn al-Ashraf, a Jewish poet who wrote an anti-Muslim poem which offended him.
"Narrated Jabir : The Prophet said, ‘Who is ready to kill Ka’b bin Ashraf (i.e. a Jew).’ Muhammad bin Maslama replied, ‘Do you like me to kill him?’ The Prophet replied in the affirmative. Muhammad bin Maslama said, ‘Then allow me to say what I like.’ The Prophet replied ‘I do (i.e. allow you).’
Narrated Jabir bin 'Abdullah: Allah's Apostle said, "Who is willing to kill Ka'b bin Al-Ashraf who has hurt Allah and His Apostle?" Thereupon Muhammad bin Maslama got up saying, "O Allah's Apostle! Would you like that I kill him?" The Prophet said, "Yes," Muhammad bin Maslama said, "Then allow me to say a (false) thing (i.e. to deceive Kab). "The Prophet said, "You may say it."
Then Muhammad bin Maslama went to Kab and said, "That man (i.e. Muhammad demands Sadaqa (i.e. Zakat) from us, and he has troubled us, and I have come to borrow something from you." On that, Kab said, "By Allah, you will get tired of him!" Muhammad bin Maslama said, "Now as we have followed him, we do not want to leave him unless and until we see how his end is going to be. Now we want you to lend us a camel load or two of food." (Some difference between narrators about a camel load or two.) Kab said, "Yes, (I will lend you), but you should mortgage something to me." Muhammad bin Mas-lama and his companion said, "What do you want?" Ka'b replied, "Mortgage your women to me." They said, "How can we mortgage our women to you and you are the most handsome of the 'Arabs?" Ka'b said, "Then mortgage your sons to me." They said, "How can we mortgage our sons to you? Later they would be abused by the people's saying that so-and-so has been mortgaged for a camel load of food. That would cause us great disgrace, but we will mortgage our arms to you." Muhammad bin Maslama and his companion promised Kab that Muhammad would return to him. He came to Kab at night along with Kab's foster brother, Abu Na'ila. Kab invited them to come into his fort, and then he went down to them. His wife asked him, "Where are you going at this time?" Kab replied, "None but Muhammad bin Maslama and my (foster) brother Abu Na'ila have come." His wife said, "I hear a voice as if dropping blood is from him, Ka'b said. "They are none but my brother Muhammad bin Maslama and my foster brother Abu Naila. A generous man should respond to a call at night even if invited to be killed." Muhammad bin Maslama went with two men. (Some narrators mention the men as 'Abu bin Jabr. Al Harith bin Aus and Abbad bin Bishr). So Muhammad bin Maslama went in together with two men, and sail to them, "When Ka'b comes, I will touch his hair and smell it, and when you see that I have got hold of his head, strip him. I will let you smell his head." Kab bin Al-Ashraf came down to them wrapped in his clothes, and diffusing perfume. Muhammad bin Maslama said. " have never smelt a better scent than this. Ka'b replied. "I have got the best 'Arab women who know how to use the high class of perfume." Muhammad bin Maslama requested Ka'b "Will you allow me to smell your head?" Ka'b said, "Yes." Muhammad smelt it and made his companions smell it as well. Then he requested Ka'b again, "Will you let me (smell your head)?" Ka'b said, "Yes." When Muhammad got a strong hold of him, he said (to his companions), "Get at him!" So they killed him and went to the Prophet and informed him. (Abu Rafi) was killed after Ka'b bin Al-Ashraf."
This is a clear case of lying endorsed by the prophet in order to achieve the objectives of Islam, therefore Muslims are permitted to lie (and kill) in defense of Muhammad and his character.