Hadith 29:118
Abu Usama narrated to us, he said: Mis'ar narrated to us, from Sa'd ibn Ibrahim, from Sa'id ibn al-Musayyib, from the one who narrated to him, that he did not hear a voice louder than his voice while he was under the banner of his father on the day of Yarmouk, and he was saying: "This is a day from the days of Allah. O Allah, send down Your victory." Meaning Abu Sufyan.
حدثنا أبو أسامة قال حدثنا مسعر عن سعد بن إبراهيم عن سعيد بن المسيب عمن حدثه أنه لم يسمع صوت أشد من صوته وهو تحت راية أبيه يوم اليرموك وهو يقول هذا يوم من أيام الله اللهم نزل نصرك يعني أبا سفيان