An Amazing Affair Related To The Dawah of Shaikhul Islaam Ibn Taymiyyah!
Ibn Abdul Haadee (rahimahullaah) said:
When he [shaikhul Islaam Ibn Taymiyyah (rahimahullaah)] entered prison, he found the prisoners preoccupied with various types of games with which they pass the time, such as chess, backgammon and the likes, among (those things that lead) to neglect of the five daily prayers. So the Shaikh [Ibn Taymiyyah(rahimahullaah)] strongly disapproved of that. He commanded them to adhere to the five daily prayers and to turn to Allaah through performance of righteous deeds, glorification of Allaah, seeking forgiveness for their sins and supplication.
He acquainted them with what they were in need of from the Sunnah, aroused their desire for it and urged them towards it, until a lot of good came about in the prison due to that which was (present) in it- such as preoccupation with knowledge and (affairs) of the Religion- and became better than many of the schools. And it became (such) that many among the prisoners chose to remain with him (Ibn Taymiyyah) after they were released, and those returning to the prison (i.e. revisiting to benefit from Ibn Taymiyyah) became so numerous that it became filled with them.
[Source: Al-Uqood Ad-Du’riyyah Fee Dhikri Manaaqib Shaikhul Islaam Ibn Taymiyyah 330-331. Abridged and slightly paraphrased]