Sahih Al Bukhari (635)

عن أبي الأسود قال أتيت المدينة وقد وقع بها مرض وهم يموتون موتا ذريعا فجلست إلى عمر (رضي الله عنه) "فمرت جنازة فأثني خيرا فقال عمر وجبت ثم مر بأخرى فأثني خيرا فقال وجبت ثم مر بالثالثة فأثني شرا فقال وجبت فقلت وما وجبت يا أمير المؤمنين قال قلت كما قال النبي (صلى الله عليه وسلم) أيما مسلم شهد له أربعة بخير أدخله الله الجنة قلنا وثلاثة قال وثلاثة قلت واثنان قال واثنان ثم لم نسأله عن الواحد"

Abu Al Aswad narrated: Once I went to Medina where there was an outbreak of disease and the people were dying rapidly. I was sitting with `Umar and a funeral procession passed by. The people praised the deceased. `Umar said: "It has been affirmed" (Paradise). Then another funeral procession passed by. The people praised the deceased. `Umar said: "It has been affirmed." (Paradise). Then another funeral procession passed by. The people praised the deceased. `Umar said: "It has been affirmed (Paradise)." Then a third funeral procession passed by and the people talked badly of the deceased. `Umar said: "It has been affirmed (Hell)." I asked Umar: "O chief of the believers! What has been affirmed?" He said: "I have said what the Prophet (peace be upon him) said. He said, 'Allah will admit into paradise any Muslim whose good character is attested by four persons.' We asked the Prophet (peace be upon him), 'If there were three witnesses only?' He said, 'Even three.' We asked, 'If there were two only?' He said, 'Even two.' But we did not ask him about one witness."