Do both fathers and sons have to finance one another’s Hajj?
Question

                Does the father have to pay for his son’s obligatory Hajj if the son is poor, and does the son have to pay for his father’s obligatory Hajj if the father is poor?
Praise be to Allah.This question was put to Shaykh Muhammad ibn Saalih al-‘Uthaymeen, may 
          Allaah preserve him, and he answered as follows:
That is not obligatory, because acts of worship are conditional upon a 
          person’s ability to do them. That ability cannot come from someone else. 
          So neither party has to do this for the other. But if the father asks 
          his son who is able to finance his Hajj to do so, the son’s responding 
          to that request will be part of the honouring of one's parents that 
          is enjoined upon children, so it is obligatory in that sense. And Allaah 
          knows best.