Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
bayhaqi:20682 – Abū Saʿīd b. Abū ʿAmr > Abū al-ʿAbbās al-Aṣam > al-Rabīʿ > al-Shāfiʿī > Marwān b. Muʿāwiyah al-Fazārī

[Machine] The people of the city decide with the oath along with the witness.  

البيهقي:٢٠٦٨٢ – أَخْبَرَنَا أَبُو سَعِيدِ بْنُ أَبِي عَمْرٍو ثنا أَبُو الْعَبَّاسِ الْأَصَمُّ أنبأ الرَّبِيعُ أنبأ الشَّافِعِيُّ أنبأ مَرْوَانُ بْنُ مُعَاوِيَةَ الْفَزَارِيُّ ثنا حَفْصُ بْنُ مَيْمُونٍ الثَّقَفِيُّ قَالَ خَاصَمْتُ إِلَى الشَّعْبِيِّ فِي مُوضِحَةٍ فَشَهِدَ الْقَائِسُ أَنَّهَا مُوضِحَةٌ فَقَالَ الشَّاجُّ لِلشَّعْبِيِّ أَتَقْبَلُ عَلَى شَهَادَةِ رَجُلٍ وَاحِدٍ؟ قَالَ الشَّعْبِيُّ قَدْ شَهِدَ الْقَائِسُ أَنَّهَا مُوضِحَةٌ وَيَحْلِفُ الْمَشْجُوجُ عَلَى مِثْلِ ذَلِكَ قَالَ فَقَضَى الشَّعْبِيُّ فِيهَا قَالَ الشَّافِعِيُّ رَحِمَهُ اللهُ وَذُكِرَ عَنْ هُشَيْمٍ عَنْ مُغِيرَةَ أَنَّ الشَّعْبِيَّ قَالَ

إِنَّ أَهْلَ الْمَدِينَةِ يَقْضُونَ بِالْيَمِينِ مَعَ الشَّاهِدِ  

See similar narrations below:

Collected by Mālik
malik:36-9 – Mālik > Abū al-Zinād

From Malik from Abu'z-Zinad that Umar ibn Abd al-Aziz wrote to Abd al-Hamid ibn Abd ar-Rahman ibn Zayd ibn al-Khattab who was the governor of Kufa, "Pronounce judgement on the basis of an oath with one witness."  

مالك:٣٦-٩ – وَعَنْ مَالِكٍ عَنْ أَبِي الزِّنَادِ

أَنَّ عُمَرَ بْنَ عَبْدِ الْعَزِيزِ كَتَبَ إِلَى عَبْدِ الْحَمِيدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ زَيْدِ بْنِ الْخَطَّابِ وَهُوَ عَامِلٌ عَلَى الْكُوفَةِ أَنِ اقْضِ بِالْيَمِينِ مَعَ الشَّاهِدِ