ENOfficial
Abu Hurayra reported that the Prophet, may Allah bless him and grant him peace, said, "When one of you gives someone an invitation and the person you invited comes with your messenger, that is his permission to enter."
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَيَّاشُ بْنُ الْوَلِيدِ، قَالَ: حَدَّثَنَا عَبْدُ الأَعْلَى، قَالَ: حَدَّثَنَا سَعِيدٌ، عَنْ قَتَادَةَ، عَنْ أَبِي رَافِعٍ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ: إِذَا دُعِيَ أَحَدُكُمْ فَجَاءَ مَعَ الرَّسُولِ، فَهُوَ إِذْنُهُ.
sunnah.com