It was narrated in Saheeh al-Bukhaari (1164) and Saheeh Muslim (4022) that Abu Hurayrah (may Allaah be pleased with him) said: “I heard the Messenger of Allaah (peace and blessings of Allaah be upon him) say: ‘The rights of a Muslim over his fellow Muslim are five: returning greetings, visiting the sick, attending funerals, accepting invitations, and saying Yarhamuk Allaah (may Allaah have mercy on you) when he sneezes.’”
The scholars divided the invitations which the Muslim is commanded to accept into two categories:
1 – Invitation to a wedding party (waleemah). The majority of scholars said that it is obligatory to accept such an invitation
, unless there is a legitimate shar’i excuse – some such excuses will be mentioned below, in sha Allaah. The evidence (daleel) that it is obligatory to accept these invitations is the hadeeth narrated by al-Bukhaari (4779) and Muslim (2585) from Abu Hurayrah, that the Prophet (peace and blessings of Allaah be upon him) said: “The worst kind of food is the food of a wedding feast that is withheld from those who would come and to which people are invited who mayrefuse it. Whoever does not accept the invitation has disobeyed Allaah and His Messenger.”
2 – Invitation to various kinds of gatherings other than wedding-feasts. The majority of scholars say that accepting these invitations is mustahabb, and no one differed from that apart from some of the Shaafa’is and Zaahiris, who said it is obligatory. If we say that it is strongly mustahabb that is close enough. And Allaah knows best.
But the scholars have stipulated conditions for accepting an invitation; if these conditions are not met then it is not obligatory or mustahabb to accept the invitation, rather it may be haraam to attend. These conditions were summed up by Shaykh Muhammad ibn ‘Uthaymeen, who said:
1- There should be nothing objectionable (munkar) in the place where the party etc. is to be held. If there is something objectionable and it is possible to remove it, then it is obligatory to attend for two reasons: to accept the invitation and to change the objectionable thing. If it is not possible to remove it then it is haraam to attend.
2- The person who invited him should not be someone whom it is obligatory or Sunnah to forsake (such as one who openly commits immoral actions or sin, where forsaking him may be of benefit in bringing about his repentance).
3- The person who invited him should be a Muslim. If he is not, then it is not obligatory to accept the invitation, because the Prophet (peace and blessings of Allaah be upon him) said: “The rights of a Muslim over his fellow Muslim are five…”
4- The food offered should be permissible for us to eat.
5- Accepting the invitation should not lead to ignoring a more important duty; if that is the case then it is haraam to accept the invitation.
6- It should not cause any trouble to the person who is invited. For example, if he needs to travel or to leave his family who need him there, and so on. (al-Qawl al-Mufeed, 3/111).
Some scholars added:
7- If the host issued a general invitation, saying that everyone is welcome, then it is not obligatory to accept the invitation.