He prayed the Maghrib prayer behind Ibn Masud, who recited "Say, He is Allah, the One" [Ikhlas 112:1].
حدثنا عبيد الله بن معاذ حدثنا أبي حدثنا قرة عن النزال بن عمار
أنه صلى خلف ابن مسعود المغرب فقرأ قل هو الله أحد
No references are available.
[Its chain is daif] Bayhaqi narrated it: 2/391, from the hadith of Abu Dawud, through the same chain. Nazzal: his status is unknown, no one deemed him trustworthy except Ibn Hibban.