(30) باب مَنْ لَمْ يَتَطَوَّعْ بَعْدَ الْمَكْتُوبَةِ
Narrated `Amr:
I heard Abu Ash-sha'tha' Jabir saying, "I heard Ibn `Abbas saying, 'I offered with Allah's Messenger (ﷺ) eight rak`at (of Zuhr and `Asr prayers) together and seven rak`at (the Maghrib and the `Isha' prayers) together.' " I said, "O Abu Ash-shatha! I think he must have prayed the Zuhr late and the `Asr early; the `Isha early and the Maghrib late." Abu Ash-sha'tha' said, "I also think so." (See Hadith No. 518 Vol. 1).
Reference: Sahih al-Bukhari 1174
In-book reference: Book 19, Hadith 52
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 2, Book 21, Hadith 270