A person with pain in his knees places a cushion on the ground to put them on during prostration; is his method of prayer valid?

The questioner : One of the brothers asked me about having pain in his joints during prostration. He is facing two options and asks: which is it, placing a prayer mat or something on the ground under his knees to ease the process of going down to the ground, or praying while sitting with his legs extended forward? One day he went to the mosque for prayer, and some people criticized him for placing a cushion, so that when he goes down, he places a thin layer... under his knees. They criticized me in the mosque regarding this matter.

The Shaykh : And what did they say to him?

The questioner : They did not say anything to him, but they criticized him. So when he prayed a second time, they criticized him even more. So he placed his legs in front of him. He was confused in the mosque where he is.

The Shaykh : He has the right to do that.

The questioner : Yes, so what is your opinion?

The Shaykh : Okay; I want to understand the first scenario, that when he places his knees or legs on, for example, a pillow or cushion, he is able to.

The questioner : Yes, exactly ... .

The Shaykh : I am not concerned with the reasoning now; I am concerned with the actual situation. Does he place his forehead on the ground?

The questioner : Yes, he places it, he places it normally. It is just a light cushion that only alleviates the pain that would occur if he placed his knees directly on the ground.

The Shaykh : There is nothing wrong with this at all. May Allah guide those who criticized him and let them fall into what is more difficult than what they did, which is praying while sitting and extending his legs toward the qiblah.