Sinan, the freed slave of Sayyiduna Wathilah (may Allah be pleased with him), narrates that a son of al-Rayyan died, and Sayyiduna Wathilah bin al-Asqa' (may Allah be pleased with him) attended his funeral. When the people returned from the graveyard, Sayyiduna Wathilah (may Allah be pleased with him) sat at the gate of Damascus. Al-Rayyan passed by him, and Sayyiduna Wathilah (may Allah be pleased with him) said to him: "O Abu Sa'id, may Allah mend your affliction and forgive your deceased." Then he said: I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever buries three of his children, Allah makes the Fire of Hell forbidden for him."
Hadith Referenceالمعجم الكبير للطبراني / باب الواو / 18451