The Prophet ﷺ said, "The best of people are my generation, then those who follow them, then those who follow them. Then lying will spread, until a man bears witness without being asked to do so and swears an oath without being asked to swear."As for the meaning of the Prophet's ﷺ statement, "The best of witnesses is the one who brings forth his testimony before being asked for it," in our view this refers to a situation in which a man has been called upon to witness something. He should then deliver his testimony and not withhold it. This is how some of the people of knowledge have interpreted the hadith.
وبيان هذا في حديث
عن النبي ﷺ قال خير الناس قرني ثم الذين يلونهم ثم الذين يلونهم ثم يفشو الكذب حتى يشهد الرجل ولا يستشهد ويحلف الرجل ولا يستحلف ومعنى حديث النبي ﷺ خير الشهداء الذي يأتي بشهادته قبل أن يسألها هو عندنا إذا أشهد الرجل على الشيء أن يؤدي شهادته ولا يمتنع من الشهادة هكذا وجه الحديث عند بعض أهل العلم