Which is more important: performing the obligatory Hajj or marrying off one's son, if there is only enough money for one of them?

It is obligatory for a man to marry off his son if the son is in need of marriage and unable to afford its expenses. This is the correct opinion of some scholars. If the father's Hajj conflicts with the son's marriage, such that the money is only sufficient for one of them, and the son is in need of marriage and fears falling into haram, then the son's marriage takes precedence over the father's Hajj. This is because safeguarding the son's chastity and protecting him from haram is an obligatory matter that cannot be delayed, while Hajj can be delayed. Hajj is not obligatory for the father unless he possesses wealth exceeding his own expenses and the expenses of those he supports, and this includes marrying off his son if he is in need of it. However, if the son does not need marriage now or does not fear falling into haram, then the father is not obligated to marry him off now, and Hajj becomes obligatory for the father.