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 (saw) is His slave and Messenger. We do not know of a hadeeth to that effect. There is no religious impediment to accepting an invitation to a wedding feast held by the brides family on the occasion of their daughter's wedding. The scholars advised that their feast is an act of the Sunnah. Shaykh Ibn ʻUthaymeen wrote:"It is obligatory to accept the invitation to a wedding banquet held by the husband. The same ruling applies to that which is given by both the husband and his wifes family together because the husband is the one who is legislatively enjoined to give a wedding banquet. The Prophet (saw) commanded ʻAbd Ar-Rahmaan ibn ʻAwf to hold a wedding banquet even with a sheep. If the brides family throws the wedding banquet and the husband is to hold another wedding banquet when his bride is brought to his house, then it is not obligatory to accept the invitation to the banquet held by the brides family; it is merely an act of the Sunnah to accept their invitation then." Perhaps the questioner is referring to the hadeeth narrated by ʻAbdullaah ibn ʻUmar which says that the Prophet (saw) said, "He who does not accept an invitation which he receives has disobeyed Allaah and His Messenger; and he who enters it without invitation enters as a thief and goes out as a raider." [Abu Daawood and others] A group of scholars labeled the chain of narration of this hadeeth as weak. Imaam Abu Daawood commented, "Abaan ibn Taariq is an unknown reporter." Al-Albaani classified it as Dha'eef (weak). If we assumed that this hadeeth was authentic, then it would have indicated that it was forbidden for the Muslim to attend a banquet without being invited, regardless of whether such a banquet was held by the husband or the wifes family. Allaah knows best. (Source: islam_web) Classified in Women and Family > Marriage Contract