Praise be to Allah.
The scholars have stated that if a man is not married, then he should give precedence to Hajj over getting married, unless he is afraid of committing shameful deeds or facing hardship, in which case he should give precedence to getting married over going for Hajj.
Ash-Shiraazi said in al-Muhadhdhab (1/197):
If he needs to get married, and he fears that he may commit shameful deeds or face hardship, then he should give precedence to getting married. End quote.
Al-Mirdaawi said in al-Insaaf (3/404):
If one who can afford to go for Hajj fears that he may commit shameful deeds or face hardship, then he should give precedence to getting married over going for Hajj, according to the correct view of our madhhab. This was stated by Imam Ahmad, and it is the view of the majority of our companions. Most of them stated that definitively, because it is obligatory in that case, and Majd narrated that there was consensus on this point, but we should be cautious with regard to claims of consensus. End quote.
The scholars of the Permanent Committee for Ifta’ said:
If a Muslim does not fear that he may commit zina, then he is obliged to give precedence to Hajj over getting married. But if he fears that he may commit that sin, then he should give precedence to getting married over going for Hajj, in order to maintain his chastity. Hajj is only obligatory for the one who is able to do it, and in this case [the one who fears that he may commit zina] is regarded as not being able to do Hajj until he takes measures to preserve his chastity. End quote.
Fataawa al-Lajnah ad-Daa’imah (23/320).
Shaykh Ibn Baaz (may Allah have mercy on him) said:
If a person has an urgent need to get married, then he must hasten to do that before going for Hajj, because in this case he is not regarded as being able to do Hajj. If he is not able to afford the costs of both getting married and going for Hajj, then he should start by getting married, so that he can preserve his chastity. End quote.
Majmoo‘ Fataawa Ibn Baaz (16/359)
See also the answer to question no. 27120.
But in the case of one who is already married, he has preserved his chastity by getting married, so what he must do is hasten to do Hajj before taking a second wife, because Hajj is one of the pillars of Islam. Allah, may He be exalted, says (interpretation of the meaning): “And [due] to Allah from the people is a pilgrimage to the House - for whoever is able to find thereto a way. But whoever disbelieves - then indeed, Allah is free from need of the worlds” [Aal ‘Imraan 3:97].
A man may be already married, but have a need for a second wife, either because he has strong desire, or because the first wife is sick, or for other reasons. In this case, he should give precedence to taking a second wife over going for Hajj, because of his need to do that.
Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said:
If the father himself needs to get married, and fears that he may commit sin if he does not get married, and he only has this money, and he can use it either to go for Hajj or to get married, then in this case we say that he should give precedence to getting married.
It comes as no surprise that you tell us that your father needs to get married and has only this money, because this happens a great deal; a man may have strong desire and one wife is not enough for him, or the first wife may have died or may be divorced, so he needs another wife. End quote.
Fataawa Noor ‘ala ad-Darb (227/30).
And Allah knows best.