It is narrated from Sayyiduna Imran bin Husayn (may Allah be pleased with him) that we were with the Messenger of Allah (peace and blessings be upon him) on a military expedition (ghazwah), or he used the word sariyyah. When it was the last part of the night, we stopped and camped at a place. Then we woke up because of the heat of the sun and were alarmed. When the Messenger of Allah (peace and blessings be upon him) woke up, he ordered us to move on from there. Then we travelled until the sun had risen quite high, and then we dismounted at another place. The people relieved themselves. Then he (peace and blessings be upon him) ordered Sayyiduna Bilal (may Allah be pleased with him) to call the adhan; he called the adhan, and we offered the two sunnah rak'ahs of Fajr. Then he (peace and blessings be upon him) ordered Sayyiduna Bilal (may Allah be pleased with him), and he called the iqamah, and he (peace and blessings be upon him) led the Fajr prayer. We said: "O Prophet of Allah! Should we not make it up tomorrow at its time as well?" The Messenger of Allah (peace and blessings be upon him) said: "Would Allah Almighty forbid you usury (riba) and then accept it from you?"
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3174