Musnad Ahmad 30:1795

Qutaybah narrated to us, Abdul Aziz narrated to us, from Suhayl, from his father, from Abu Hurayrah, that the Messenger of Allah, may Allah bless him and grant him peace, said to some women of the Ansar: "There is not one of you whose three children die, and she seeks the reward from Allah for them, except that she will enter Paradise." A woman among them said: "Or two, O Messenger of Allah?" He said: "Or two."