A person is not obliged to save money to be able to perform Hajj
2-1-2016 | IslamWeb
Question:
Assalaamu alaykum dear brothers and scholars. My wife has already performed her Hajj and wants to perform Hajj for her deceased father. However, she ignores whether her father had enough money at any stage of his life in order for Hajj to have been an obligation on him at that time. She does know that her father was well established and earned enough to be able to save the money necessary to perform Hajj during his lifetime. The question is: Can Hajj be considered an obligation on her father after his death given this explanation? May Allaah reward you.
Answer:
All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad 
is His slave and Messenger.
Hajj becomes obligatory for whoever is able to perform it at the time when the people go out for it. So whoever owns what he needs for his trip back and forth, such as the means of transportation, food, drink and clothing, while this is in surplus of the expenses of those whom he is obliged to spend on, such as his wife and children, throughout his trip back and forth, then Hajj is obligatory on him.
If a person does not meet the above requirements, then Hajj is not obligatory on him.
Also, he is not obliged to acquire the causes that make him capable, by saving the money with which he would be able to perform Hajj, because the well-known fundamental rule is that what is lacking something to become obligatory is not obligatory.
Ibn 'Uthaymeen 
was asked, "Is a person obliged to collect money so that he would be able to pay zakah, and is a person when a whole lunar year has elapsed obliged to do what is necessary [in order to be able] to give out the zakah?"
He answered:
“He is not obliged to collect money in order to pay zakah on it, but if a person has the nisaab (minimum amount liable for zakah), then he must do what is required of him to pay zakah.
The difference between the two is that what is lacking something to become obligatory is not obligatory, but if something is actually obligatory, then all what is needed to fulfill it becomes obligatory. Hence, collecting money so that one becomes able to pay the zakah means acquiring something to make the zakah obligatory, and this is not an obligation.
The same thing applies to Hajj: should we say that a person is obliged to collect money in order to perform Hajj? Or should we say: if he possesses the money, he must perform Hajj?
The answer is that if he owns money, then he must perform Hajj, but the first matter [i.e. collecting money in order to perform Hajj] is not an obligation.” [End of quote]
Also, Haashiyat Al-Jamal reads: “...If one is able to perform Hajj in Ramadan and then became poor before Shawwaal, then he is not considered able (to perform Hajj).” [End of quote]
Based on the above, the fact that your wife's father "was well established and earned enough to be able to save the money necessary to perform Hajj during his lifetime" does not necessarily mean that Hajj had become obligatory on him during his life.
As regards after his death, then he is no longer held accountable, and if something was not obligatory during one’s life, it does not become obligatory on him after his death.
However, if your wife wants to perform Hajj on behalf of her father, then this is acceptable regardless of whether or not Hajj was obligatory on him during his life.
Ibn Qudaamah said, “As for the dead, it is permissible to perform Hajj on his behalf without his permission regardless of whether this is the obligatory Hajj or an optional one, because the Prophet ordered us to perform Hajj on behalf of the dead, and it is known that there was no permission needed, and what is permissible in regard to an obligatory act of worship is also permissible in regard to an optional similar act of worship, just like the charity.” [Al-Mughni]
Allaah knows best.