[Muslim].
It is narrated by Bukhari from Anas bin Malik (May Allah be pleased with him): We were coming back from the battle of Tabuk with the Prophet (ﷺ) when he remarked, "There are people whom we left behind in Al- Madinah who accompanied us in spirit in every pass and valley we crossed. They remained behind for a valid excuse."
((ورواه البخاري)) عن أنس رضي الله عنه قال: رجعنا من غزوة تبوك مع النبي صلى الله عليه وسلم فقال: " إن أقواماً خلفنا بالمدينة ما سلكنا شعباً ولا وادياً إلا وهم معنا، حبسهم العذر".
Reference | : Riyad as-Salihin 4 |
In-book reference | : Introduction, Hadith 4 |