عَنْ زَيْدِ بْنِ خَالِدٍ اَلْجُهَنِيِّ رضى الله عنه
أَنَّ اَلنَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «أَلَا أُخْبِرُكُمْ بِخَيْرِ اَلشُّهَدَاءِ? اَلَّذِي يَأْتِي بِشَهَادَتِهِ قَبْلَ أَنْ يُسْأَلَهَا»
The Prophet (sallallahu alayhi wa sallam) said: “Shall I not inform you who is the best witness? He is the one who produces his testimony before he is asked for it.”.
Bulugh al-Maram 1596, Book 14, Judgments, Hadith 18. 1 min read