We have mentioned the narrations from Bukhari about the battle of Hunain. These narrations prove that most the companions run away from the battle field and Umar bin Khattab was also among those Companions who flew away. Please read these narrations.
آپ اس لنک سے بھی وضاحت کے ساتھ پڑھ سکتے ہیں کہ عمر بن خطاب دوسرے صحابہ کے ساتھ حنین کی جنگ سےبھاگ نکلے
آپ بخاری کی دونوں روایات پڑھکر جان جایں گے عمر بن خطاب ان لوگوں میں شامل تھے جو بھاگ رہے تھے
URDU TRANSLATION:
Quran mentions the situation about Hunain (9:25) God has helped you on many occasions including the day of Hunayn (name of a place near Mecca). When you were happy with the number of your men who proved to be of no help to you and the whole vast earth seemed to have no place to hide you (from your enemies) and you turned back in retreat.