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.
bayhaqi:130Abū al-Ḥusayn b. Bishrān > Ismāʿīl b. Muḥammad al-Ṣaffār > Saʿdān b. Naṣr > Sufyān > Ḥaddathūnā > Zayd b. Aslam And Lam Asmaʿh from his father

[Machine] "Where did you get this from? I have never seen water from a well or water from the sky that is better than this." He said, "I got it from the house of this elderly Christian woman." So, when she performed ablution, he came to her and said, "O elderly woman, embrace Islam and you will be safe. Allah has sent Muhammad with the truth." Then, she uncovered her head and it appeared as white as a palm splinter. She said, "Am I going to die now?" Umar replied, "Allah knows best."  

البيهقي:١٣٠وَأَخْبَرَنَا أَبُو الْحُسَيْنِ بْنُ بِشْرَانَ أنا إِسْمَاعِيلُ بْنُ مُحَمَّدٍ الصَّفَّارُ ثنا سَعْدَانُ بْنُ نَصْرٍ ثنا سُفْيَانُ قَالَ حَدَّثُونَا عَنْ زَيْدِ بْنِ أَسْلَمَ وَلَمْ أَسْمَعْهُ عَنْ أَبِيهِ قَالَ لَمَّا كُنَّا بِالشَّامِ أَتَيْتُ عُمَرَ بِمَاءٍ فَتَوَضَّأَ مِنْهُ فَقَالَ

مِنْ أَيْنَ جِئْتَ بِهَذَا؟ فَمَا رَأَيْتُ مَاءَ بِئْرٍ وَلَا مَاءَ سَمَاءٍ أَطْيَبَ مِنْهُ؟ قَالَ قُلْتُ مِنْ بَيْتِ هَذِهِ الْعَجُوزِ النَّصْرَانِيَّةِ فَلَمَّا تَوَضَّأَ أَتَاهَا فَقَالَ أَيَّتُهَا الْعَجُوزُ أَسْلِمِي تَسْلَمِي بَعَثَ اللهُ بِالْحَقِّ مُحَمَّدًا ﷺ فَكَشَفَتْ رَأْسَهَا فَإِذَا مِثْلُ الثُّغَامَةِ قَالَتْ وَأَنَا أَمُوتُ الْآنَ؟ قَالَ فَقَالَ عُمَرُ اللهُمَّ اشْهَدْ