مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4152
Musnad of Abdullah bin Mas'ood
It was narrated from ‘Abdullah (رضي الله عنه) from the Prophet (ﷺ), that He said: "I will reach the Cistern ahead of you, and some men of you will be brought to me then they will be snatched away from me. I will say: 'O Lord, my companions!' It will be said: “You do not know what they did after you were gone.
Musnad Ahmad 4180Its isnad is saheeh, al-Bukhari (7049) and Muslim (2297)]