The husband of Sayyidah Furay'ah bint Malik (may Allah be pleased with her) was martyred at Taraf al-Qadum, and she asked the Prophet (peace and blessings be upon him) for permission to go to her family. He (peace and blessings be upon him) said: "No, (not) until the waiting period ('iddah) is completed."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21454