Chapter 4: From it (i.e. the previous chapter subject) [Among That Lying Will Spread Until A Man Will Testify While His Testimony Was Not Requested And A Man Will Take An Oath While His Oath Was Not Sought] - كتاب الشهادات عن رسول الله صلى الله عليه وسلم
حَدِيثِ عُمَرَ بْنِ الْخَطَّابِ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " خَيْرُ النَّاسِ قَرْنِي ثُمَّ الَّذِينَ يَلُونَهُمْ ثُمَّ الَّذِينَ يَلُونَهُمْ ثُمَّ يَفْشُو الْكَذِبُ حَتَّى يَشْهَدَ الرَّجُلُ وَلاَ يُسْتَشْهَدُ وَيَحْلِفُ الرَّجُلُ وَلاَ يُسْتَحْلَفُ " . وَمَعْنَى حَدِيثِ النَّبِيِّ صلى الله عليه وسلم " خَيْرُ الشُّهَدَاءِ الَّذِي يَأْتِي بِشَهَادَتِهِ قَبْلَ أَنْ يُسْأَلَهَا " . هُوَ عِنْدَنَا إِذَا أُشْهِدَ الرَّجُلُ عَلَى الشَّىْءِ أَنْ يُؤَدِّيَ شَهَادَتَهُ وَلاَ يَمْتَنِعَ مِنَ الشَّهَادَةِ هَكَذَا وَجْهُ الْحَدِيثِ عِنْدَ بَعْضِ أَهْلِ الْعِلْمِ . كَمُلَ وَالْحَمْدُ لِلَّهِ كِتَابُ الشَّهَادَاتِ وَيَلِيهِ كِتَابُ الزُّهْدِ
Clarification of this is in the Hadith of 'Umar bin Al-Khattab, from the Prophet(s.a.w) who 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 testifies while his testimony was not requested, and a man will take an oath while an oath was not sought."