Shaykh Muḥammad Taqī al-Dīn al-Ḥilālī:

My friend and I were transferred to teach in the Great Mosque of Mecca, and it is true that teaching in the Great Mosque of Mecca is a great trial for the teacher. Often, you’d find a teacher, well-known for his knowledge and virtue, sitting and teaching in Mecca’s Great Mosque, with gatherings of no more than ten people. Then you’d find another teacher, less famous and knowledgeable than the first, but with hundreds of students listening to his lecture. These affairs happen in accordance with what Allah ﷻ has ordained for everyone. As with shopkeepers, one shop is frequented by many customers who generate sales, whereas the shop next door, despite stocking the same or even better goods, is inactive and receives no customers.

I was among the blessed ones, and all praise is due to Allah. Hundreds of people would attend my lesson in front of the Gate of Ibrāhīm. I’m not sure why, except that I used to speak in a dialect that all Arabs could understand. The other teachers’ lack of attendance was due to them speaking in a local dialect [that could only be understood] by a specific group of people.