Tirmidhi

English Commentary:
1:
In this hadith, the word "hasir" is mentioned, and in the previous one, the word "khumrah" appears.
The difference is that a "khumrah" is small, and only one person can perform prayer on it, whereas a "hasir" is large and long, allowing more than one person to pray on it.
Both were made from palm leaves.
In this era, prayer mats (musalla) of various sizes are made from burlap, plastic, wool, and cotton.
Fine and exquisite carpets are also produced,
which are used in mosques and homes.
In the aforementioned hadith, there is evidence for the permissibility of these.

Hadith Commentary:
Benefits and Issues:
➊
It is understood from the hadith that a person's urine is impure, and if the mosque becomes impure, it should be washed and purified immediately.
➋
One should adopt a gentle attitude with the uninformed and the ignorant, and when choosing between two harms, the lesser harm should be accepted.
➌
If impurity falls on the ground, it is sufficient to pour water over it to remove it; there is no need to dig up the ground.
➍
From another hadith, it is understood that an ignorant person should be taught the ruling with gentleness and affection.
➎
The primary purpose of building mosques is the remembrance of Allah, prayer (salah), admonition and advice, religious education, and recitation of the Qur'an.
And they should be protected from every action that is contrary to the greatness and sanctity of the mosques.

Benefit:
(Haseer)
It is a large mat.
One can stand on it to perform prayer, or more than one person can perform prayer on it.