(a) It is narrated from Sayyiduna Ali (may Allah be pleased with him) that on the day of the Trench, the Messenger of Allah (peace and blessings be upon him) said: "These enemies kept us occupied from the middle prayer (the Asr prayer); may Allah fill their houses and their graves with fire." Then he (peace and blessings be upon him) offered the Asr prayer between Maghrib and Isha.
(b) It is also narrated with a weak chain that he broke off the first prayer, first prayed Asr, and then offered the Maghrib prayer.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3190