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:2106 – Abū ʿAbdullāh al-Ḥāfiẓ And ʾAbū Saʿīd b. Abū ʿAmr > Abū al-ʿAbbās > al-Rabīʿ b. Sulaymān > Ibn Wahb > Yūnus Waʿamrū b. al-Ḥārith Wamālik b. Anas > Ibn Shihāb > Ḥumayd b. ʿAbd al-Raḥman b. ʿAwf > ʿUmar b. al-Khaṭṭāb And ʿUthmān b. ʿAffān Kānā Yuṣallīān Ṣalāh al-Maghrib Ḥīn Yanẓurān > al-Layl al-Aswad Qabl

[Machine] To break their fast and then break it again after the prayer.  

البيهقي:٢١٠٦ – وَأَخْبَرَنَا أَبُو عَبْدِ اللهِ الْحَافِظُ وَأَبُو سَعِيدِ بْنُ أَبِي عَمْرٍو قَالَا ثنا أَبُو الْعَبَّاسِ ثنا الرَّبِيعُ بْنُ سُلَيْمَانَ ثنا ابْنُ وَهْبٍ أَخْبَرَنِي يُونُسُ وَعَمْرُو بْنُ الْحَارِثِ وَمَالِكُ بْنُ أَنَسٍ عَنِ ابْنِ شِهَابٍ قَالَ أَخْبَرَنِي حُمَيْدُ بْنُ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ أَنَّ عُمَرَ بْنَ الْخَطَّابِ وَعُثْمَانَ بْنَ عَفَّانَ كَانَا يُصَلِّيَانِ صَلَاةَ الْمَغْرِبِ حِينَ يَنْظُرَانِ إِلَى اللَّيْلِ الْأَسْوَدِ قَبْلَ

أَنْ يُفْطِرَا ثُمَّ يُفْطِرَانِ بَعْدَ الصَّلَاةِ  

See similar narrations below:

Collected by Mālik
malik:18-9 – Mālik > Ibn Shihāb > Ḥumayd b. ʿAbd al-Raḥman > ʿUmar b. al-Khaṭṭāb And ʿUthmān b. ʿAffān Kānā Yuṣallīān al-Maghrib Ḥīn Yanẓurān > al-Layl al-Aswad Qabl

Yahya related to me from Malik from Ibn Shihab from Humayd ibn Abd ar-Rahman that Umar ibn al-Khattab and Uthman ibn Affan would pray maghrib when they saw the night darkening, before they broke their fast, and that was during Ramadan.  

مالك:١٨-٩ – وَحَدَّثَنِي عَنْ مَالِكٍ عَنِ ابْنِ شِهَابٍ عَنْ حُمَيْدِ بْنِ عَبْدِ الرَّحْمَنِ أَنَّ عُمَرَ بْنَ الْخَطَّابِ وَعُثْمَانَ بْنَ عَفَّانَ كَانَا يُصَلِّيَانِ الْمَغْرِبَ حِينَ يَنْظُرَانِ إِلَى اللَّيْلِ الأَسْوَدِ قَبْلَ

أَنْ يُفْطِرَا ثُمَّ يُفْطِرَانِ بَعْدَ الصَّلاَةِ وَذَلِكَ فِي رَمَضَانَ