مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4163
Musnad of Abdullah bin Mas'ood
It was narrated from 'Abdullah from The Prophet (ﷺ) who said: "If you are three..." and he narrated a similar report.
Musnad Ahmad 4191Its isnad is saheeh, al-Bukhari (2181) and Muslim (6290).