The Book of Prayers
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ شَقِيقٍ، عَنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ، قَالَ كُنَّا إِذَا جَلَسْنَا مَعَ النَّبِيِّ صلى الله عليه وسلم فِي الصَّلاَةِ . بِمِثْلِ حَدِيثِ مَنْصُورٍ وَقَالَ " ثُمَّ يَتَخَيَّرُ بَعْدُ مِنَ الدُّعَاءِ " .Abdullah b. Mas'ud reported:We were sitting with the Apostle (ﷺ) in prayer, and the rest of the hadith is the same as narrated by Mansur He (also said): After (reciting tashahud) he may choose any prayer
From Sahih Muslim, whose reports the scholars accept as authentic.