´Zaid bin Khalid Al-Juhani said that he heard the Messenger of Allah (ﷺ) say:` “The best of witnesses is the one who gives his testimony before he is asked for it.”
Hadith Referenceسنن ابن ماجه / كتاب الأحكام / 2364
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم