مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4320
Musnad of Abdullah bin Mas'ood
It was narrated that ‘Abdullah said: I know the pairs (of soorahs) that the Messenger of Allah (ﷺ) used to recite in one rak'ah.
Musnad Ahmad 4350Its isnad is saheeh, al-Bukhari (4996) and Muslim (822)]