Riyad as-Salihin: The Book of Jihad – Hadith No. 663 — Jabir (May Allah be pleased with him) reported: We accompanied the Prophet (ﷺ)… (Hadith No. 663)

Jabir (May Allah be pleased with him) reported: We accompanied the Prophet (ﷺ) in an expedition when he (ﷺ) said, "Some people have remained behind us in Al-Madinah, and we never cross a valley but they are with us. They share the reward with us because they have been held back by valid excuse."In another narration the wordings are: "…by any genuine excuse."In another narration the wordings are: "They are your partners in reward.".

Explanation:

Reference: Riyad as-Salihin, The Book of Jihad, Hadith No. 663