If there is a man who has saved a sum of money to perform the obligatory Hajj (i.e., Hajj for the first time), and after five years he becomes entitled to enter the randomized lottery for allocating Hajj visas. In the meantime, he has a son who is single and of marriageable age. If he gets his son married, that sum could go short and so he may not be able to perform Hajj. In this case, which takes precedence? Should he do the obligatory Hajj or get his son married?