Musnad Ahmad 344
It was narrated that Simak said:
I heard ‘Iyad al-Ash`ari say: i was present at al-Yarmouk and we had five commanders over us: Abu `Ubaidah bin al-Jarrah, Yazeed bin Abi Sufyan, Ibn Hasanah, Khalid bin al-Waleed and `Iyad - and this `Iyad was not the one who narrated reports to Simak. - `Umar (رضي الله عنه) said: If fighting occurs, then your commander is Abu `Ubaidah. So we wrote to him, saying: We are facing death; and we asked him for reinforcements. He wrote to us, saying: I have received your letter asking for reinforcements and I can tell you about who has the greatest support and the most ready troops.
Allah, may He be glorified and exalted, ask Him for support, for Muhammad (ﷺ) was caused to prevail on the day of Badr with fewer than your numbers. When this letter of mine reaches you, fight them without referring back to me. So we fought them, and we defeated them, pursuing and killing them for four parasangs, and we acquired wealth (booly). They discussed the issue (of booty) and ‘Iyad suggested to us that we should give ten for every head. And Abu ʼUbaidah said: Who will compete with me (in a horse race)? A young man said: I will, if you don`t get angry. Then he beat him, and I saw the two braids of Abu ‘Ubaidah flying as he raced behind him on an Arabian horse.
حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ سِمَاكٍ، قَالَ سَمِعْتُ عِيَاضًا الْأَشْعَرِيَّ، قَالَ شَهِدْتُ الْيَرْمُوكَ وَعَلَيْنَا خَمْسَةُ أُمَرَاءَ أَبُو عُبَيْدَةَ بْنُ الْجَرَّاحِ وَيَزِيدُ بْنُ أَبِي سُفْيَانَ وَابْنُ حَسَنَةَ وَخَالِدُ بْنُ الْوَلِيدِ وَعِيَاضٌ وَلَيْسَ عِيَاضٌ هَذَا بِالَّذِي حَدَّثَ سِمَاكًا قَالَ وَقَالَ عُمَرُ رَضِيَ اللَّهُ عَنْهُ إِذَا كَانَ قِتَالٌ فَعَلَيْكُمْ أَبُو عُبَيْدَةَ قَالَ فَكَتَبْنَا إِلَيْهِ إِنَّهُ قَدْ جَاشَ إِلَيْنَا الْمَوْتُ وَاسْتَمْدَدْنَاهُ فَكَتَبَ إِلَيْنَا إِنَّهُ قَدْ جَاءَنِي كِتَابُكُمْ تَسْتَمِدُّونِي وَإِنِّي أَدُلُّكُمْ عَلَى مَنْ هُوَ أَعَزُّ نَصْرًا وَأَحْضَرُ جُنْدًا اللَّهُ عَزَّ وَجَلَّ فَاسْتَنْصِرُوهُ فَإِنَّ مُحَمَّدًا صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَدْ نُصِرَ يَوْمَ بَدْرٍ فِي أَقَلَّ مِنْ عِدَّتِكُمْ فَإِذَا أَتَاكُمْ كِتَابِي هَذَا فَقَاتِلُوهُمْ وَلَا تُرَاجِعُونِي قَالَ فَقَاتَلْنَاهُمْ فَهَزَمْنَاهُمْ وَقَتَلْنَاهُمْ أَرْبَعَ فَرَاسِخَ قَالَ وَأَصَبْنَا أَمْوَالًا فَتَشَاوَرُوا فَأَشَارَ عَلَيْنَا عِيَاضٌ أَنْ نُعْطِيَ عَنْ كُلِّ رَأْسٍ عَشْرَةً قَالَ وَقَالَ أَبُو عُبَيْدَةَ مَنْ يُرَاهِنِّي فَقَالَ شَابٌّ أَنَا إِنْ لَمْ تَغْضَبْ قَالَ فَسَبَقَهُ فَرَأَيْتُ عَقِيصَتَيْ أَبِي عُبَيْدَةَ تَنْقُزَانِ وَهُوَ خَلْفَهُ عَلَى فَرَسٍ عَرَبِيٍّ‏.‏