Sunan An-Nasai, Chapter: The Book of the Times (of Prayer)

"We were with the Messenger of Allah (saw) and we were prevented from praying Zuhr, Asr, Maghrib and Isha. I felt very upset about that and I said to myself: 'We are with the Messenger of Allah (saw) and (fighting) for the sake of Allah.' Then the Messenger of Allah (saw) commanded Bilal to say the Iqamah and he led us in praying Zuhr. Then he said the Iqamah and he led us in praying Asr. Then he said the Iqamah and he led us in praying Maghrib. Then he said the Iqamah and he led us in praying Isha. Then he went around among us and told us: 'There is no group on Earth who is remembering Allah, the Mighty and Sublime, except you.'" (Hasan)