Musnad Ahmad 30:2076

Musa ibn Dawud narrated to us, he said: It was read to Malik, from Suhayl, from his father, from Abu Hurayrah, that the Prophet, may Allah bless him and grant him peace, said: "Indeed, the gates of Paradise are opened on Monday and Thursday. Then, every servant who does not associate anything with Allah is forgiven, except for a man between whom and his brother there is enmity. It is said: 'Delay these two until they reconcile,' [repeated] twice."