Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Prophet Muhammad (peace and blessings be upon him) said: "The gates of Paradise are opened every Monday and Thursday, and Allah forgives every servant who does not associate anything with Allah, except for the person who has enmity with his brother. It is said regarding them: 'Keep checking on both of them until they reconcile.' (Their forgiveness will not be granted.) 'Keep checking on both of them until they reconcile.' (Their forgiveness will not be granted.)"
Hadith Referenceصحیح ابن حبان / كتاب الحظر والإباحة / 5661
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «غاية المرام» (412): م.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط الصحيح