Musnad Ahmad 33:173

Muhammad ibn Abi ‘Adi narrated to us, from Muhammad ibn Ishaq, Muhammad ibn Ibrahim narrated to me, from Mahmud ibn Labid, from Jabir, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: "Whoever has three of his children die, and he seeks the reward for them [from Allah], will enter Paradise." He said: We said: "O Messenger of Allah, and two?" He said: "And two." Mahmud said: So I said to Jabir: "I think if you had said one, he would have said one." He said: "And I, by Allah, think that as well."