Musnad Ahmad 1018:42

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Zayd Abu al-Hawwari, from Abu al-Siddiq, from the companions of the Prophet (may Allah bless him and grant him peace), from the Prophet (may Allah bless him and grant him peace) that he said: "The poor of the believers will enter Paradise before their rich by four hundred years." He said: So I said, "Indeed, al-Hasan mentions forty years." He said, from the companions of the Prophet (may Allah bless him and grant him peace), from the Prophet (may Allah bless him and grant him peace): "Four hundred years." He said: "Until the rich believer says: 'I wish I had been a dependent.'" He said: We said, "O Messenger of Allah, name them for us by their names?" He said: "They are those who, when there is a hardship, they are sent for it, and when there is a spoil, it is sent to others besides them, and they are those who are barred from the doors."