The Messenger of Allah (sal Allahu alaihi wa sallam) said: “The dust (stirred up) in the Way of Allah and the Fire of Jahannam will never come together in the chest of a slave.” [Nasai]
Abdullah Ibn al-Mubarak not only defended Islamic knowledge from being polluted by falsehood, heresy and deviancy, but he also defended Islam physically. He was a scholar known for partaking in battles and defending the Muslim lands. Ibn Kathir said: “He was known for participating in battles and Hajj very often.” [Al-Bidayah wal Nihayah]
Imam al-Dhahabi calls Ibn al-Mubarak “the pride of the Mujahideen (fighters).” [Tadhkirat al-Huffadh] He comments, “He was the leader of the brave… he used to perform Hajj one year and in the next year, he would be stationed in battles in the Way of Allah.” [Al-Ibar fi Akhbar man Ghabar]
He was particularly known for his Jihad against the Romans and just like he was an Imam in Islamic knowledge, he was also an Imam in warfare, and just as he taught Hadith and Fiqh, he also taught the people heroism and bravery. Hajj one year and Jihad the next was a principle he lived by and this was to such an extent that his death came just as he had returned from battle.
When in Tarsus, Ibn al-Mubarak wrote a letter to his friend al-Fudayl ibn Iyadh (who was known for his worship in Makkah and Madinah), encouraging him to partake in Jihad and not to be satisfied with simply worshipping Allah in the mosques. Ibn Abi Sukaynah said, “In Tarsus in the year 177 AH, Ibn al-Mubarak gave me a letter with the following verses. I bid farewell to him and went to deliver it to al-Fudhayl ibn Iyadh.
O Worshipper of the two Holy Mosques!
Were you to see us, you would realise your worship is mere play
For the one whose tears fall down his cheek (in worship)
Then in turn, our blood flows down our necks (in battles)
Or him whose horse tires in pursuing pretence
Then our horses toil on the morning of combat
For you is the smell of fragrance, but our fragrance
Is the dust and dirt kicked off, which is more pleasant
And indeed, the words of our Prophet have reached us
A correct and truthful statement, which cannot be denied
The dust stirred up by the Horse of Allah which enters a man's nose
Can never coexist with the smoke of a blazing fire (Hell)
This is the Book of Allah which shall judge between us
Surely, the martyr is not dead and this can never be refuted
“So I met al-Fudhayl in the Haram (Makkah) with the letter and when he read it, tears came to his eyes and he said, ‘Indeed, Abu Abdur-Rahman (Ibn al-Mubarak) has told the truth and he has certainly advised (me).’”
[Tafseer Ibn Kathir]