Safiyyah bint Abi Ubayd narrates; it is narrated from Hafsah (may Allah be pleased with her) or Aishah (may Allah be pleased with her), or both, that the Messenger of Allah (peace and blessings be upon him) said: "It is not permissible for a woman who believes in Allah and His Messenger to mourn for a deceased person for more than three days, except for her husband."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 19663