Is it permissible for a sick person who is unable to move for ablution to pray without it?

If the brother is unable to move, the questioner should help him with ablution by giving him water to perform Wudu, or by directly assisting him. If Wudu harms him, he should be given something from the earth to perform Tayammum on it. If he is unable to perform Tayammum, then Tayammum should be performed for him. The incapacitated person should pray according to his ability, as Allah Almighty says: "So fear Allah as much as you are able," and the Prophet, peace and blessings be upon him, said: "And when I command you to do something, do of it as much as you are able."