The Messenger of Allah ﷺ used to pray sixteen rakahs at night, in addition to the obligatory prayers.
حدثنا عبد الله حدثنا أبو عبد الرحمن بن عمر حدثنا عبد الرحيم يعني الرازي عن العلاء بن المسيب عن أبي إسحاق عن عاصم بن ضمرة
كان رسول الله ﷺ يصلي من الليل ست عشرة ركعة سوى المكتوبة
Its isnad is sahih. Abu Abdul-Rahman bin Umar is Abdullah bin Umar bin Muhammad bin Aban, nicknamed Mishkadana, discussed previously at 1071. Abdul-Rahim Razi is Abdul-Rahim bin Sulayman Marwazi, called Ashall. He is trustworthy. Ala bin Musayab bin Rafi Asadi is trustworthy and reliable. This hadith is a repetition of 1233, and it contains the same error in the text as that one, "from the night" when the correct wording is "from the day," which will come in the next one with the correct wording.