Sahih al-Bukhari 2081
Narrated Abu Mas`ud:
An Ansari man, called Abu Shu'aib, came and told his butcher slave, "Prepare meals sufficient for five 
persons, for I want to invite the Prophet (ﷺ) along with four other persons as I saw signs of hunger on his 
face." Abu Shu'aib invited them and another person came along with them. The Prophet (ﷺ) said (to Abu 
Shu'aib), This man followed us, so if you allow him, he will join us, and if you want him to return, he 
will go back." Abu Shu'aib said, "No, I have allowed him (i.e. he, too, is welcomed to the meal).
حَدَّثَنَا عُمَرُ بْنُ حَفْصٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا الأَعْمَشُ، قَالَ حَدَّثَنِي شَقِيقٌ، عَنْ أَبِي مَسْعُودٍ، قَالَ جَاءَ رَجُلٌ مِنَ الأَنْصَارِ يُكْنَى أَبَا شُعَيْبٍ فَقَالَ لِغُلاَمٍ لَهُ قَصَّابٍ اجْعَلْ لِي طَعَامًا يَكْفِي خَمْسَةً، فَإِنِّي أُرِيدُ أَنْ أَدْعُوَ النَّبِيَّ صلى الله عليه وسلم خَامِسَ خَمْسَةٍ، فَإِنِّي قَدْ عَرَفْتُ فِي وَجْهِهِ الْجُوعَ‏.‏ فَدَعَاهُمْ، فَجَاءَ مَعَهُمْ رَجُلٌ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏
"‏ إِنَّ هَذَا قَدْ تَبِعَنَا، فَإِنْ شِئْتَ أَنْ تَأْذَنَ لَهُ فَأْذَنْ لَهُ، وَإِنْ شِئْتَ أَنْ يَرْجِعَ رَجَعَ ‏"‏‏.‏ فَقَالَ لاَ، بَلْ قَدْ أَذِنْتُ لَهُ‏.‏