As-salamu Alaikum, some Orientalists said that Prophet Muhammad (peace be upon him) was literate. They've mentioned two examples: The Treaty of Hudaibiah and two versions I've read: A. The prophet signed “son of Abdullah” B. The prophet omitted the word “apostle of God”. Another story is that at his death bed, the prophet asked for a pen and ink to write who was to be his successor. Hope to hear from you soon. Thank you, wa-salam. P.S.: Glad Ask About Islam is available.

Short Answer:

• Yes, Prophet Muhammad was, indeed, illiterate.
• Like the vast majority of people during his time in his area, he could neither read nor write.
• In situations when some history recorded him requesting pen and paper to write, he was actually requesting someone to write for him.
• It is true that some Orientalists use the two occasions – as you have mentioned – to prove that Prophet Muhammad (peace be upon him) was, in fact, literate. However, by analyzing each of these incidents, one can easily discover the fallacies in their allegations.

Treaty of Hudaybiyah

Firstly, in the Treaty of Hudaybiyah, the Prophet ﷺ did not write the treaty, but, his cousin, Ali (may Allah be pleased with him) did.To prove this, we can look to the incident with Suhail: While writing the treaty, Suhail ibn `Amr (a man from the Quraish side) rejected that the Prophet would have his name signed as the messenger or apostle of Allah (rasoulu Allah). 

Suhail asked to have it changed to “Muhammad, son of Abdullah”. Prophet Muhammad ﷺ then asked Ali to omit “rasoulu Allah” (the messenger of Allah). Yet, Ali did not like the idea of omitting it and said:

By Allah, I swear I will never omit rasoulu Allah

And this is the part of the story the Orientalists usually – deliberately – do not mention: when Ali refused to omit rasoulu Allah,  said to Ali: “show it to me.”

After Ali showed it to him, the Prophet used his thumb to hide those words, so as to show he didn’t want them included. (Al- Bukhari)

Upon His Death Bed

As for the second incident, the report–of which the authenticity is doubted by many scholars–says that Prophet Muhammad asked for a pen and a paper to write a letter stating who would be his successor. 

In dealing with this incident, Orientalists totally ignore the fact that in the Arabic language, as well as culture, you can simply use the tools of a profession to indicate the profession.

Thus, Prophet Muhammad ﷺ, by asking for a pen and a paper, was asking for someone to write the letter for him. 

Furthermore, who were near the Prophet ﷺ were not astonished by the Prophet’s request for one reason: they were aware of exactly what he meant.

Also, throughout history, none of the Arabic speaking people ever used this incident to doubt the illiteracy of the Prophet. 

The Quran: A Gift From God to an Illiterate Man

In fact, it is a miracle that despite his illiteracy, he received the Quran as a last testament. This is a sign that the Quran is a divine revelation. 

Indeed, as no illiterate man could come up with such a beautifully accomplished and complete text.

Also,, narrated in the Quran – from Adam to Jesus – could not have been read by Muhammad in the Old or New Testament. This is because he could not read in the first place. 

And Allah knows best.I hope this helps answer your question.