وَعَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: مَنْ دُعِيَ فَلَمْ يُجِبْ فَقَدْ عَصَى اللَّهَ وَرَسُولَهُ وَمَن دَخَل٘ عَلى غَيْرِ دَعْوَةٍ دَخَلَ سَارِقًا وَخَرَجَ مُغِيرًا. رَوَاهُ أَبُو دَاوُد(مشکوۃ المصابیح:۳۲۲۲)
Translation
It is narrated from Hazrat Abdullah bin Umar (may Allah be pleased with him) that the Holy Messenger (peace and blessings of Allah be upon him) said: "Whoever is invited and does not accept, he has disobeyed Allah and His Messenger; and whoever participates in a feast without being invited, he entered as a thief and left as a robber." (Abu Dawud) (Ar-Rafeeq Al-Faseeh / Vol: 16 / Pg: 372)