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.
malik:43-39Yaḥyá > Mālik > Yaḥyá b. Saʿīd > Saʿīd b. al-Musayyab > ʿUmar b. al-Khaṭṭāb Qatal Nafar Khamsah Aw Sabʿah Birajul Wāḥid Qatalūh Qatl Ghīlah

Yahya related to me from Malik from Yahya ibn Said from Said ibn al-Musayyab that Umar ibn al-Khattab killed five or seven people for one man whom they had killed secretly by trickery. Umar said, "Had all the people of Sana joined forces against him, I would have killed them all."  

مالك:٤٣-٣٩وَحَدَّثَنِي يَحْيَى عَنْ مَالِكٍ عَنْ يَحْيَى بْنِ سَعِيدٍ عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ أَنَّ عُمَرَ بْنَ الْخَطَّابِ قَتَلَ نَفَرًا خَمْسَةً أَوْ سَبْعَةً بِرَجُلٍ وَاحِدٍ قَتَلُوهُ قَتْلَ غِيلَةٍ

وَقَالَ عُمَرُ لَوْ تَمَالأَ عَلَيْهِ أَهْلُ صَنْعَاءَ لَقَتَلْتُهُمْ جَمِيعًا