Musnad Ahmad 3988
Musnad of Abdullah bin Mas'ood
It was narrated that 'Abdullah bin Mas'ood said: We were with the Messenger of Allah(ﷺ) and we were kept from praying Zuhr, ‘Asr, Maghrib and 'Isha. And that upset me a great deal, then I said: We are with the Messenger of Allah and (fighting) for the sake of Allah. Then the Messenger of Allah (ﷺ) instructed Bilal to give the iqamah (call immediately preceding the prayer) and he led us in praying Zuhr, then he gave the iqamah and he led us in praying ‘Asr; then he gave the iqamah and he led us in praying Maghrib, then he gave the iqamah and he led us in praying ‘Isha'. Then the Messenger of Allah (ﷺ) went around us, then he said: “There is no band of people on earth who are remembering Allah, may He be glorified and exalted, except you."