Asim bin Damra reported,
We asked Ali 
about the voluntary prayers of the Prophet ﷺ during the day. He said, "You will not be able to keep up with it."We said, "Tell us about it, and we will take from it what we are able."He said, "When the Prophet ﷺ had prayed Fajr, he would wait until the sun reached the position from over here," meaning from the east, "equivalent to its position from over here," meaning from the west, "at the time of Asr. Then he would stand and pray two rakahs. Then he would wait until the sun reached the position from over here," meaning from the east, "equivalent to its position from over here," meaning from the west, "at the time of Zuhr. Then he would stand and pray four rakahs, and four rakahs before Zuhr when the sun had passed its zenith, and two rakahs after it, and four rakahs before Asr. He would separate every two rakahs by saluting the angels brought near, the prophets, and those who follow them among the believers and Muslims."Ali said, "Those are sixteen rakahs of voluntary prayer that the Prophet ﷺ performed during the day, and few are those who maintain them regularly."Waki narrated to us from his father, who said, Habib bin Abu Thabit said to Abu Ishaq when he related this hadith to him, "Abu Ishaq, this hadith of yours is worth its weight in gold, enough to fill your mosque."
Ahmad 650
Sahihحدثنا وكيع حدثنا سفيان وإسرائيل وأبي عن أبي إسحاق
عن عاصم بن ضمرة قال
سألنا عليا رضي الله عنه عن تطوع النبي ﷺ بالنهار فقال إنكم لا تطيقونه قال قلنا أخبرنا به نأخذ منه ما أطقنا قال كان النبي ﷺ إذا صلى الفجر أمهل حتى إذا كانت الشمس من ها هنا يعني من قبل المشرق مقدارها من صلاة العصر من هاهنا من قبل المغرب قام فصلى ركعتين ثم يمهل حتى إذا كانت الشمس من هاهنا يعني من قبل المشرق مقدارها من صلاة الظهر من هاهنا يعني من قبل المغرب قام فصلى أربعا وأربعا قبل الظهر إذا زالت الشمس وركعتين بعدها وأربعا قبل العصر يفصل بين كل ركعتين بالتسليم على الملائكة المقربين والنبيين ومن تبعهم من المؤمنين والمسلمين قال قال علي رضي الله عنه تلك ست عشرة ركعة تطوع النبي ﷺ بالنهار وقل من يداوم عليها. حدثنا وكيع عن أبيه قال قال حبيب بن أبي ثابت لأبي إسحاق حين حدثه يا أبا إسحاق يسوى حديثك هذا ملء مسجدك ذهبا
Its isnad is sahih. Waki's father is Jarra bin Mulayh Ruasi, who is trustworthy. He has been criticized without justification, and Bukhari mentioned him in Tarikh al-Kabir 1/2/226-227 without noting any criticism, nor did he mention him among the weak narrators. Waki transmits this hadith from three people, his father, Sufyan Thawri, and Israil. Abu Ishaq is Subayi.Tirmidhi related part of this hadith under numbers 424, 429, 598, and 599, by way of Sufyan and by way of Shuba, from Abu Ishaq, and he graded it hasan, saying, "It has been related from Abdullah bin Mubarak that he used to weaken this hadith. He weakened it, in our view, and Allah knows best, because nothing like this is related from the Prophet ﷺ except by this route, from Asim bin Damra, from Ali, and Asim bin Damra is trustworthy according to some scholars." See our commentary on Tirmidhi 2:289, 293, 494-495.As for the statement of Habib bin Abu Thabit to Abu Ishaq, "Your hadith here is worth a mosque full of gold," by this he means to affirm the hadith as sahih and to strengthen it. Al-Hafiz made a rather strange error in Tahdhib 2:146, taking this statement as praise for Harith Awar, and mentioning it in his biographical entry, saying, "I say, in Musnad Ahmad, from Waki, from his father, it states that Habib bin Abu Thabit said to Abu Ishaq, when he narrated from Harith, from Ali, concerning Witr, 'O Abu Ishaq, your hadith here is worth a mosque full of gold!'"This is a shift of attention on his part, may Allah have mercy on him, for as you can see, this statement actually concerns the hadith of Asim bin Damra, but the hadith of Harith on Witr came right after it, so Al-Hafiz's attention shifted during transcription, and he assumed the statement came after the hadith of Harith rather than before it.His word "yuswa" is with fatha on the ya and the waw, with a silent sin between them, meaning "is worth." In Lisan 19:136, Layth said, "Yuswa is an irregular form, and one does not say from it 'sawiya' or 'sawaya,' just as 'nakraa' occurs as an irregular form, and one does not say for its verbal noun 'ankara,' rather they say 'nakira' and do not say 'yankuru.'" Azhari said, "Their saying 'la yuswa,' I reckon it is a dialect of the people of Hijaz, and it has also been related from Shafii."This will also come again at 1201, 1202, 1207, 1233, 1240, 1241, 1260, and 1375, and we have explained Al-Hafiz's error in his transmission of it as praise for the hadith of Harith Awar, so see what conclusively establishes the truth of what we have said at 1207.