Sunan Ibn Majah, Chapter: The Chapters on Ascetism (Zuhd)

"We were with the Messenger of Allah (saw) on one of his campaigns. He passed by some people and said: Who are these people? They said: We are Muslims. There was a woman putting wood in her oven, and a son of hers was with her. When the flames got higher, she moved him away. She came to the Prophet (saw) and said: Are you the Messenger of Allah? He said: Yes. She said: May my father and mother be ransomed for you. Is not Allah the Most Merciful of those who show mercy? He said: Yes indeed. She said: Is not Allah more Merciful than a mother to her child? He said: Yes indeed. She said: A mother would not throw her child into the fire. The Messenger of Allah (saw) lowered his head and wept. Then he looked up at her and said: Allah does not punish any of His slaves except those who are defiant and rebellious, who rebel against Allah and refuse to say: La ilaha illallah."