Wedding parties are among the things in which it is prescribed to express happiness and joy and to instil that in the family and the wife, but that does not mean that one should fall into extravagance or spend unnecessarily. The argument that it is only once in a lifetime cannot be an excuse tospend too much. Being extravagant only once is not allowed and is haraam, just as being extravagant more than once is repeatedly falling into something that is not allowed and is haraam.
The scholars are still urging people not to be extravagant in wedding parties and other expenses that have to do with weddings in general. They suggest that this is one of the factors that make the issue of marriage complicated for those who want to get married, to such an extent that the numbers of young women who remain unmarried have increased.
Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allah have mercy on him) was asked:
What is your opinion on expensive dowries and extravagance in wedding parties, especially preparations for what is called the honeymoon, which includes high expenses? Does Islam approve of this?
He (may Allah have mercy on him) replied:
Expensive dowries and extravagance in wedding parties are things that are contrary to sharee‘ah. The most blessed marriage is that which is affordable; the less the expenses are, the greater the blessings. This is something that in most cases is the fault of women, because women are the ones who force their husbands to pay for expensive parties that are not allowed in sharee‘ah. This is something that is included in the words of Allah, may He be glorified and exalted (interpretation of the meaning): “…but waste not by extravagance, certainly He (Allâh) likes not Al-Musrifûn (those who waste by extravagance)” [al-A‘raaf 7:31]. Many women force their husbands to do that and say “So and so had such and such in her party” and so on.
But what is required in such matters is to act in the way prescribed in Islam and not overstep that mark or be extravagant, because Allah – may He be glorified and exalted – has forbidden extravagance and has said that He does not like those who waste by extravagance.
With regard to what is called the “honeymoon”, it is even worse and more reprehensible, because it is an imitation of the non-Muslims and it is a great waste of money. It also leads to neglect of many religious matters, especially if this time is spent in a non-Muslim country, after which they come back with habits and customs that are harmful to them and to their society. These are matters which are dangerous to the ummah. But if the man were to travel with his wife to do ‘Umrah or to visit Madinah, there is nothing wrong with that, in sha Allah.
Fataawa Islamiyyah, 3/176