It is believed that this is the tomb of the Job. In the Bible, it says that be was blameless and that Satan appeared before the Lord and ask if he could, well pretty much destroy his life; and that Job would turn from God when these things happened. However Job did not turn from God and again the enemy lost.
In Islam, it is believed that Job prayed towards Jerusalem everyday but when God appeared to him that he turned and started praying towards Mecca. Interesting right? It is also believed that if as a Muslim you pray next to a Prophet's tomb, then you will receive all of his goodness, virtue and wisdom. So while we were there, we actually experienced this happening.
So while they were praying we were praying for the one and true Living God to present Himself to them.