مُسْنَدُ أَحْمَدَ
Musnad Ahmad 4136
Musnad of Abdullah bin Mas'ood
It was narrated from 'Abdullah (رضي الله عنه), that He used to recite this verse: “then is there anyone who will remember (or receive admonition) (fahal min muddakir)?” (al-Qamar 54:17), with (the letter) dal.
Musnad Ahmad 4163Its isnad is saheeh, al-Bukhari (4873) and Muslim (823)]