It is narrated from Sayyidah Furay'ah bint Malik (may Allah be pleased with her), the sister of Abu Sa'id al-Khudri (may Allah be pleased with him), that her husband went out in search of his (runaway) slaves and was killed in the outskirts of al-Qadum. So she came to the Prophet (peace and blessings be upon him) and told him (peace and blessings be upon him) her own circumstances and those of her husband, and mentioned moving to her brothers. The Prophet (peace and blessings be upon him) gave her permission; but when she turned to leave, he (peace and blessings be upon him) called out to her and said: "Remain in your house until the waiting period ('iddah), that is, four months and ten days, is completed."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21448