مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4203
Musnad of Abdullah bin Mas'ood
It was narrated that 'Abdullah said: The Messenger of Allah (ﷺ) said one thing and I say another. The Messenger of Allah (ﷺ) said: "Whoever dies associating something with Allah will enter Hell.” And I say whoever dies not associating anything with Allah will enter Paradise.
Musnad Ahmad 4231lts isnad is saheeh, al-Bukhari (1238) and Muslim (92)]