Is it permissible to drink and bathe from a spring of water with the intention of healing, and is it the spring mentioned in Surat (Sad), and is the grave located there the grave of the Prophet Ayyub (Job)?

There is no validity to the existence of the well known as Job's Well, and the place where Job (peace be upon him) bathed is unknown. The mere fame of a place or its being circulated among people does not make it a reality. There is no grave on earth that has been agreed upon as the grave of a prophet, except for the grave of our Prophet Muhammad (peace and blessings be upon him), and the grave of Abraham (peace be upon him) in the known cave. As for the graves of the rest of the prophets, they are unknown.