Donating a Mus'haf or a Prayer Mat as an Endowment to the Mosque
11-12-2018 | IslamWeb
Question:
Salam aleikum If one gives prayer mat or quran to a mosque or to Another muslim . Does that Count as sadaqa jariyah that every time somebody pray or recite quran Will i get ajer bcz i gave them quran / prayer mat
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
With regard to the Mus-haf (the hardcopy of the Quran); if someone makes an endowment of the Mus-haf to the mosque, or gives it to a person to recite from it, with the intention that it (the Mus-haf) is an endowment, then this will be a continuous charity whose reward continues and the person who endowed it will receive the reward, Allah willing.
The same thing applies to the prayer mat if he donates it to someone to pray on it. However, if he donated it to the mosque, then if the mosque is not carpeted and people in the mosque need a prayer mat to pray on, then donating it as an endowment to this mosque is permissible and the person will be rewarded.
However, if the mosque is already carpeted and does not need any mat, then donating a prayer mat to it is meaningless and the person who donated it may not be rewarded. This is because it is not prescribed to place a prayer mat above the carpet in order to pray on it, since the carpet of the mosque is enough.
Ibn Al-Qayyim 
said in his book entitled Ighaathatul-Lahfaan min Masaa-id Ash-Shaytaan: "Some people insist to pray on a prayer mat while the Prophet never performed the prayer on a special mat and no carpet would be spread for him. Instead, he used to pray on the ground, and at times he would prostrate while it was muddy. He prayed on Haseer (mats made of date-palm leaves or straw, etc.); he used to pray on whatever was available; if there was nothing spread on the ground, then he would pray on the ground."
For more benefit, please refer to Fatwa 248656.
Allah knows best.