The feast hosted by the groom after the wedding is known as Walima. This feast is in accordance with the practice of the Prophet (Sunnah).
For the bride's family to host a feast, or to solicit one from them, amounts to an indirect form of dowry. During the time of the Prophet (peace be upon him), there was no custom of the bride's family hosting the wedding feast.
There is no obligation for the groom to host a lavish feast, nor is he required to go into debt to provide one. The Sunnah is fulfilled even if one serves a simple meal to just a few people, according to one's means.
When the Prophet (peace be upon him) married Safiyyah, he served only a small amount of flour and dates as the Walima feast.
Narrator: Anas (RA)
Source: Bukhari 371, 2893
When the Prophet (peace be upon him) got married, he served two Mudds (approximately one liter) of wheat as the Walima feast.
Narrator: Safiyyah (RA)
Source: Bukhari 5172
The Prophet (peace be upon him) never hosted a feast as substantial as the one he held for his marriage to Zaynab. When he married Zaynab, he served a sheep as the wedding feast.
Narrator: Anas (RA)
Source: Bukhari 5168, 5171, 7421
The largest Walima feast the Prophet (peace be upon him) ever hosted consisted of a single sheep; this was the most lavish feast he provided. Therefore, one should avoid extravagance in the name of the wedding feast.
When inviting guests to the Walima feast, no distinction should be made between the rich and the poor.
The Prophet (peace be upon him) stated that a Walima feast to which only the wealthy are invited while the poor are excluded is the worst kind of meal. Narrator: Abu Hurairah (RA)
Source: Bukhari 5177
If a person is invited to a Walima feast, they should not decline it. The aforementioned Hadith states that the Prophet (PBUH) said that whoever does not accept a Walima invitation has disobeyed Allah and His Messenger.
Although accepting the invitation is necessary, one may—and indeed should—avoid it if activities contrary to religious teachings are taking place at the venue, or if the host is a person of bad character.
I prepared a feast and invited the Prophet (PBUH). Upon arriving and seeing an image [or figure] in my house, he turned back and left.
Narrator: Ali (RA)
Source: Nasa'i 5256
Following this practice of the Prophet (PBUH), the Companions of the Prophet also adopted a strict stance regarding this matter.
A man invited Abu Mas'ud (RA) to a feast. Abu Mas'ud asked, "Are there any statues or figures in the house?" The man replied, "Yes." Abu Mas'ud stated, "In that case, I will not come until they are smashed and thrown away," and he only attended after they had been destroyed.
Source: Bayhaqi, Volume 7, Page 268
During my father's time, we organized a feast and invited people; Abu Ayyub (RA) was among the invitees. Upon entering the house, he saw that the walls were decorated with silk cloth. Seeing me, he asked, "Abdullah! Are you decorating the walls with silk?" My father replied, "The women have overpowered us [in this matter]." Abu Ayyub (RA) said, "I do not fear that women will overpower you [in a way that excuses this]; furthermore, I will not eat your food." They turned back, stating that they would not even enter the house.
Tabarani’s *Al-Mu’jam al-Kabir*, Volume 4, Page 118.
Prophet Muhammad (PBUH) and his companions declined an invitation for a reason that we would consider quite trivial.
Yet, we attend—without the slightest hesitation—feasts that are rife with extravagance, un-Islamic practices, and wasteful spending on a scale hundreds of times greater than that. We ought to reflect deeply on whether this is right.