Silsilat al-Ahadith al-Sahihah

Sayyiduna Anas bin Malik (may Allah be pleased with him) reports: A man came to the Messenger of Allah (peace and blessings be upon him) and asked about coitus interruptus (‘azl). The Messenger of Allah (peace and blessings be upon him) said: “If it is decreed for a child to be born from the semen, then even if you spill it on a rock, Allah the Exalted will bring forth a child from it. Allah the Exalted will surely create every soul that He has destined to create.”