Riyad as-Salihin, Book 3, Hadith 739 (In-Book) ⓘ

Abu Mas'ud Al-Badri (May Allah be pleased with him) reported: A man prepared some food especially for the Prophet and invited him along with four others. But a man accompanied him. Having arrived at the door, Messenger of Allah said to the host, "This person has followed us. You may allow him, if you like, and if you like he will return." He said: "O Messenger of Allah, I allow him, too." [Al-Bukhari and Muslim].

عن أبى مسعود البدرى رضى الله عنه قال‏:‏ دعا رجل النبي صلى الله عليه وسلم لطعام صنعه له خامس خمسة، فتبعهم رجل، فلما بلغ الباب، قال النبي صلى الله عليه وسلم‏:‏ ‏ "‏إن هذا تبعنا؛ فإن شئت أن تأذن له، وإن شئت رجع‏" ‏ قال‏:‏ بل آذن له يا رسول الله ‏.‏ ‏.‏