“…It is known that he is from the most knowledgeable of scholars in the history of Islam. I mean, if you were to take the ten most notable scholars of the Muslims throughout history, an-Nawawi would be one of them. He wrote a commentary on ‘Sahih Muslim,’ and he wrote his book ‘al-Majmu” in Fiqh, regarding which Ibn Kathir said: “Nothing was ever written to match its brilliance.” And yes, nothing was ever written like this book.
When you read anything by an-Nawawi, you feel as if you are a plant that is being watered, as he delves deeply into meanings and concepts. Add to this that he abstained from the worldly pleasures, he was a devout worshipper, he would enjoin what was good, and he would forbid what was wrong. He would stand up to the rulers in the peak of their power. One time, the lamp he was using went out, and he lit it with his hand – he continued writing using light that was emanating from his hand!
He came into conflict with Dhahir Baybras, the ruler of Sham and Egypt. Dhahir Baybras requested a fatwa from the scholars that money should be collected in order to prepare an army to fight the Tatars in 658 H. When the Tatars occupied Baghdad and advanced upon Palestine and turned towards Sham, he requested a fatwa while the Tatars were in Palestine that money should be collected to purchase weapons.
Every single scholar issued the fatwa except for an-Nawawi. He said: “I will not provide you with such a fatwa.”
Dhahir asked: “Why not? I want to purchase arms for this struggle, and you refuse to issue a fatwa for it? The entire Ummah and Religion will be exposed to loss.”
He replied: “Because you came to us as a slave who owned nothing, and I see that you now own gardens, servants, slave girls, silver, and gold. So, if you sell all of these things and still need money after that, I will issue the fatwa you seek.”
He said: “Leave Sham.”
And he left and went to a small village in Nawa (his hometown). The scholars came to Dhahir Baybras and said to him: “The scholars of Sham are nothing without Muhi ad-Din an-Nawawi.” He replied: “Bring him back.” They then went to an-Nawawi and said: “Come back, O Muhi ad-Din.” an-Nawawi said: “By Allah, I will not go back while Dhahir is in it,” and Allah fulfilled his oath: Dhahir died a month later, and an-Nawawi returned to Sham.
This is an-Nawawi, the devout worshipper, the scholar, the zahid, the scholar of Usul, Fiqh, and Hadith. Look at the blessing that is in his books…ya Salam! Look at the barakah: his book ‘al-Majmu” has provided much benefit, his book ‘Riyad as-Salihin,’ his book of forty Hadith, his book ‘al-Adhkar’ – you can feel the barakah in his books. No books have been so widely distributed as the books of an-Nawawi…”
['Fi Dhilal Surat at-Tawbah'; p. 67-68]