(19) باب مَا يَفْعَلُ الضَّيْفُ إِذَا تَبِعَهُ غَيْرُ مَنْ دَعَاهُ صَاحِبُ الطَّعَامِ وَاسْتِحْبَابُ إِذْنِ صَاحِبِ الطَّعَامِ لِلتَّابِعِ
Abu Mas'ud Ansari reported that a person from the Ansar who was called Abu Shu'aib had a slave who was a butcher (by profession). He (Abu Mas'ud) saw Allah's Messenger (ﷺ) and found signs of hunger on his face. He said to the servant:
0 ye, prepare for us food sufficient for five persons, for I intend to invite Allah's Apostle (ﷺ) who would be the fifth amongst the five. He (the narrator) reported that he then prepared the food and came to Allah's Apostle (ﷺ) and invited all the five (including him) who was the fifth amongst them to the feast. A man followed him and when Allah's Apostle (ﷺ) reached the door, he said: This man has followed us; if you like you may permit him (to join the meal) and if you like he can go back. Thereupon the person said: Allah's Messenger, I permit him.
Reference: Sahih Muslim 2036 a
In-book reference: Book 36, Hadith 183
USC-MSA web (English) reference(deprecated numbering scheme): Book 23, Hadith 5051