if the mountain won't come to Muhammad, Muhammad must go to the mountain
If one can't have one's way, one must give in. For example, Since you can't come here for the holiday, I'll go to your house—if the mountain won't come to Muhammad, Muhammad must go to the mountain. This expression is based on a tale that Muhammad once sought proof of his teachings by ordering a mountain to come to him. When it did not move, he maintained that God had been merciful, for if it had indeed moved they all would have been crushed by it.
[ Late 1500s