What is the ruling on wearing trousers and a long shirt that covers the trousers?

The student : If I assume that I wore trousers like these and put on a long shirt like this that covers them, is it permissible for me to wear trousers, for example jeans, even if they are covered by this thing? Is there no harm in that?

The Shaykh : We need to see why he is wearing the trousers.
The student : Sometimes I wear them because they fit tightly around my waist, and I want to put something in a pocket that does not fit in the pockets of the shirt or the dishdasha.

The Shaykh : In the sarwal.
The student : I do not have pockets in the sarwal.

The Shaykh : You do not have any? You can put some in.
The student : He is a tailor, O Shaykh. The tailor’s door broke.
Another student: I want to understand, O Shaykh.
The student : I have jeans.

The Shaykh : What kind of trousers do you have?
The student : Jeans.
Another student: Like these, I mean.

The Shaykh : Yes.
The student : Do I wear them and put this over them, or do I not wear them?

The Shaykh : Do not wear them. There is no obstacle until you tear them, and then...
The student : By Allah, O Shaykh, I mean, since I became a Muslim, I have not bought anything new, if Allah wills.

The Shaykh : Praise be to Allah.