Musnad Ahmad 31:306

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from 'Abd al-Rahman ibn al-Asbahani, from Dhakwan, from Abu Sa'id al-Khudri, that the women said: "The men have overcome us regarding you, O Messenger of Allah, so appoint for us a day, O Messenger of Allah, on which we may come to you." So he appointed a time for them, and he commanded them and exhorted them. He said: "There is no woman among you who loses three of her children, except that they will be a veil for her from the Fire." A woman said: "Or two? For I have lost two." The Messenger of Allah, peace and blessings of Allah be upon him, said: "Or two."