عَنْ زَيْدِ بْنِ خَالِدٍ اَلْجُهَنِيِّ ‏- رضى الله عنه ‏- أَنَّ اَلنَّبِيَّ ‏- صلى الله عليه وسلم ‏-قَالَ: {"أَلَا أُخْبِرُكُمْ بِخَيْرِ اَلشُّهَدَاءِ? اَلَّذِي يَأْتِي بِشَهَادَتِهِ قَبْلَ أَنْ يُسْأَلَهَا"} رَوَاهُ مُسْلِم ٌ 1‏ .‏‏1 ‏- صحيح.‏ رواه مسلم ( 1719 )‏.‏
Translation
Narrated 'Abdullah bin 'Amr (RA)

Allah's Messenger (ﷺ) said: "It is not permissible to accept the testimony of a man or a woman who does not fulfill their trusts, or of one who harbors a grudge against his brother, or the testimony of one who is dependent on a family (to testify) for members of the family."[Reported by Ahmad and Abu Dawud].