Narrated AbuHurayrah:

People with a bier passed by the Messenger of Allah ﷺ. They (the companions) spoke highly of him. He said: Paradise is certain for him. Then some people with another (bier) passed by him. They spoke very badly of him. He said: Hell is certain for him. He then said: Some of you are witness to others.

حَدَّثَنَا حَفْصُ بْنُ عُمَرَ، حَدَّثَنَا شُعْبَةُ، عَنْ إِبْرَاهِيمَ بْنِ عَامِرٍ، عَنْ عَامِرِ بْنِ سَعْدٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ مَرُّوا عَلَى رَسُولِ اللَّهِ ﷺ بِجَنَازَةٍ فَأَثْنَوْا عَلَيْهَا خَيْرًا فَقَالَ " وَجَبَتْ " . ثُمَّ مَرُّوا بِأُخْرَى فَأَثْنَوْا عَلَيْهَا شَرًّا فَقَالَ " وَجَبَتْ " . ثُمَّ قَالَ " إِنَّ بَعْضَكُمْ عَلَى بَعْضٍ شُهَدَاءُ " .