It was with patience and determination that the Hebrew Children marched around the walls of Jericho seven times before it fell.  It wasn’t until Naaman obeyed the Prophet Elisha and resolutely dipped himself into the Jordan River seven times that he was healed of his leprosy.  And in this passage,  it was a persistent and tenacious  Prophet Elijah that prayed seven times before the rain came and ended the drought.  The number seven doesn’t matter here as much as the idea of not giving up!  For all these examples show that perseverance pays off in the end, and that God rewards the single-minded.