Can I Do Hajj for My Parents?
Question

I have done Hajj, praise be to Allah, but my parents both died without having done Hajj. I want to do Hajj on their behalf – should I start with my mother? When I have done Hajj on behalf of one of them, I want to borrow money and delegate someone to perform Hajj on behalf of the other.
Praise be to Allah.Mother takes precedence over father with regard to good treatment 
The mother’s right to being honoured is greater than the father’s right. 
Al-Bukhari (5971) and Muslim (2548) narrated that Abu Hurayrah (may Allah be pleased with him) said: A man came to the Messenger of Allah (peace and blessings of Allah be upon him) and said: “O Messenger of Allah, who among the people is most deserving of my good company?” He said, “Your mother.” He said, “Then who?” He said, “Then your mother.” He said, “Then who?” He said, “Then your mother.” He said, “Then who?” He said, “Then your father.” 
Ibn Battal said: 
“What this means is that the mother is entitled to three times more honouring than the father. That is because of the difficulties of pregnancy, then childbirth, then breastfeeding. This is something that applies only to the mother and she goes through suffering because of it. Then the father participates in raising the child. This is also referred to in the verse in which Allah says (interpretation of the meaning): 
“And We have enjoined on man (to be dutiful and good) to his parents. His mother bore him in weakness and hardship upon weakness and hardship, and his weaning is in two years.” [Luqman 31:14]
The command to be dutiful and good applies equally to both here, but the mother is singled out with regard to these three things. 
Al-Qurtubi said: 
“What is meant is that the mother is entitled to a greater share of her child’s honour, and that takes precedence over the father’s right in the case of conflict.” 
‘Iyad said: 
“The majority are of the view that the mother takes precedence over the father with regard to honour and good treatment. Or it was said that they are equal in this regard. But the former view is the one that is correct.” (Fath al-Bari)
Al-Nawawi said in Sharh Muslim: 
“The reason why the mother is given precedence here is because she puts a great deal of effort into caring for him, shows compassion towards him and serves him. She suffers when she carries him (in her womb), and when she gives birth to him, and when she breastfeeds him, then she brings him up, serves him, nurses him and so on.”
Shaykh Ibn ‘Uthaymin (may Allah have mercy on him) was asked a similar question and he replied: 
“Do Hajj on behalf of your mother first , because the mother has more right to be honoured than the father. This has to do with the obligatory Hajj. But if the mother’s Hajj is nafil and the father’s Hajj is obligatory, then start with the obligatory Hajj on behalf of the father. But do not borrow money in order to send someone to perform Hajj on behalf of your father. If next year comes and you are able to do Hajj, then do Hajj on behalf of your father. Doing Hajj on his behalf yourself is better than delegating someone else to do it, because your sincerity towards your father is greater than anyone else’s. Hence we say: it is not permissible for you to borrow money in order to delegate someone to perform Hajj on behalf of your father . Rather you should do Hajj on behalf of your mother this year, so long as you are able to, and next year if you are able to, do Hajj on behalf of your father.” (Fatawa Ibn ‘Uthaymin, 21/134)