بُلُوغُ الْمَرَامِ
Bulugh al-Maram 464
The Book of Prayer
وَعَنْ أَبِي بُرْدَةَ عَنْ أَبِيهِ سَمِعْتُ رَسُولَ اَللَّهِ - صلى الله عليه وسلم -يَقُولُ: { هِيَ مَا بَيْنَ أَنْ يَجْلِسَ اَلْإِمَامُ إِلَى أَنْ تُقْضَى اَلصَّلَاةُ } رَوَاهُ مُسْلِمٌ, وَرَجَّحَ اَلدَّارَقُطْنِيُّ أَنَّهُ مِنْ قَوْلِ أَبِي بُرْدَةَ . [1] .
Narrated Abu Burdah (RA) from his father's: I heard Allah's Messenger (ﷺ) say, "That time is between the time when the Imam sits down and the end of the prayer." [Reported by Muslim. ad-Daraqutni held that the stronger view is that it is the saying of Abu Burdah].
Sunnah.com reference: Book 2, Hadith 385