I heard the Messenger of Allah ﷺ say, "It is not lawful for a Muslim to shun another Muslim for more than three nights. If they remain estranged beyond three nights, both of them have strayed from the truth as long as they continue their estrangement. The first of them to return is the one whose return becomes his expiation. If he greets the other with peace and the other refuses to return the greeting, the angels return the greeting to the one who offered it, while Satan responds to the other. If they die in their state of estrangement, they will never be united together in Paradise."
حدثنا روح بن عبادة قال حدثنا شعبة عن يزيد الرشك قال شعبة قرأته عليه قال سمعت معاذة العدوية قالت سمعت
سمعت رسول الله ﷺ يقول لا يحل لمسلم أن يهجر مسلما فوق ثلاث ليال فإن كان تصارما فوق ثلاث فإنهما ناكبان عن الحق ما داما على صرامهما وأولهما فيئا فسبقه بالفيء كفارته فإن سلم عليه فلم يرد عليه ورد عليه سلامه ردت عليه الملائكة ورد على الآخر الشيطان فإن ماتا على صرامهما لم يجتمعا في الجنة أبدا
Its isnad is sahih. Yazid Rishk is Yazid bin Abu Yazid Dubai, Abu Azhar Basri, the trustworthy, devout worshipper whom they praised, and his hadith is found in the works of the group. Muazah Adawiyyah is the daughter of Abdullah, Umm Sahba, and she is trustworthy, her hadith being found in the works of the group. The hadith has already appeared at 12627.