Imam Abdur Razzaq, who is the teacher of Imam Bukhari's teachers, narrates a Hadith on the authority of Hadhrat Saib Bin Yazid in his Musannaf:
عن السائب بن يزيد قال : كنا ننصرف من القيام على عهد عمر وقد دنا فروع الفجر ، وكان القيام على عهد عمر ثلاثة وعشرين ركعة.
Translation: It has been narrated on the authority of Hadhrat Saib bin Yazid (May Allah be well pleased with him), he says: In the era of ‘Umar, we would return from the night’s prayers when the time for Fajr would be near and in his era, the Salaat of the night would be 23 Raka’at (i.e. 20 Raka’at of Taraweeh and 3 of Witr)
Apart from 20 Raka’at of Taraweeh, this Hadith establishes that long Raka’at and intense recitation of the Holy Quran was the habit of the Sahabah.
The Hadith of Hadhrat Saib Bin Yazid (May Allah be well pleased with him) and the opinions of the Muhadditheen (Hadith experts)
Imam Nawawi (May Allah be well pleased with him) has mentioned this Hadith as rigorously-authenticated (Sahih) in his book "Khulasatul Ahkam"
رَوَاهُ الْبَيْهَقِيّ بِإِسْنَاد صَحِيح .
Translation: Imam Baihaqui has narrated this Hadith using a rigorously-authenticated (Sahih) chain of narration.
(Khulasatul Ahkaam, Kitab Us Salaat, Hadith No: 1961)
This opinion of Imam Nawawi (May Allah shower His mercy on him) has been related by Imam Zail‘ai (May Allah shower His mercy on him) in “Nasab Ur Raya Fi Takhreejil Ahadithil Hidayah,” Allama Ibn Hamam in Fath Ul Qadeer, Allama Badruddin ‘Aini (May Allah shower His mercy on him) in ‘Umdatul Qari, Imam Suyuti in AL Havi Lil Fatawa, Mulla ‘Ali Qari (May Allah shower His mercy on him) in Mirqaatul Mafateeh Sharh Mishkaatul Masabeeh.