Salaam aqeel
I got the following from the Net:
Following extracts clearly show that Hz. Umar (may Allah be pleased with him) was with the Prophet (peace be upon him) in the heat of the battle at the most critical time.
*At those awkward moments of that day, a group of Muslim heroes gathered around the Prophet [pbuh] forming a shield to protect him from the idolaters. Some of them were Abu Dujana, Mus‘ab bin ‘Umair, ‘Ali bin Abi Talib, Sahl bin Haneef, Malik bin — Sinan the father of Abu Sa‘îd Al-Khudri, Umm‘Amara, Nusaiba bint Ka‘b Al-Mâziniya, Qatada bin An-Nu‘man, ‘Umar bin Al-Khattab, Hatib bin Abi Balta‘a and Abu Talha.
Muhammad bin Maslamah brought him fresh water to drink. The Prophet [pbuh] drank and supplicated Allâh to provide him with good things. [As-Seerat Al-Halabiyah 2/30] Owing to the wounds and their bad effects on his body, the Messenger of Allâh [pbuh] led his followers in prayer in a sitting posture and so did the Muslims. [Ibn Hisham 2/87]
When the preparations of the idolaters for departure came to an end, Abu Sufyan went up the mountain and called out: “Is Muhammad [pbuh] among you?” They did not answer him.
Then he asked “Is Ibn Abi Quhafah (i.e. Abu Bakr) among you?” They did not answer.
He asked again: “Is ‘Umar bin Al-Khattab among you?” They did not answer him; for the Prophet [pbuh] forbade them answering him.
He only asked about those three. That is because he and his people knew quite well that the call to Islam depended to a large degree on those men.
Abu Sufyan then said: “As for those three, we have relieved you of.” ‘Umar could not help but talking, so he said, “O enemy of Allâh, those whom you have just mentioned, I tell you that they are still alive. Allâh has maintained what you hate.”
Abu Sufyan answered: “The mutilation of your killed is something I did not order it; but it did not displease me.” Then he shouted: “Hubal (an idol), let it be sublime!” The Prophet [pbuh] said: “Why do you not reply?” “What shall we say?” They asked him. “Say: Allâh is more Sublime and Exalted and Mightier as well.”
He said: “Al-‘Uzza (i.e. an idol) is ours but you have no ‘Uzza.” “Why do you not reply?”
The Prophet [pbuh] said. “What shall we say?” They inquired. He said: “Say Allâh is our Protector, but you have no protector.”
Abu Sufyan said: “Well deeds! Today is a vengeance for Badr Day. This for that. War is attended with alternate success.” ‘Umar’s reply was: “No. They are not the same. Our killed men are housed in Paradise; but yours are in Fire.”
Then Abu Sufyan said: “Come on, ‘Umar!” The Messenger of Allâh [pbuh] said: “Go and see what the matter is.”
He went there. Abu Sufyan asked him: “I beseech you by Allâh’s Name to tell me the truth: Have we killed Muhammad [pbuh]?” ‘Umar said: “O Allâh, ‘No’ and now he is listening to you words.” He said: “For me, you are more truthful than Ibn Qami’a, and even more reliable.” [Ibn Hisham 2/93,94; Za’d Al-Ma’ad 2/94; Sahih Al-Bukhari 2/579]
Ibn Ishaq said: When Abu Sufyan and those who were with him were leaving he called out notifying: “We will meet again at Badr next year.” The Messenger of Allâh [pbuh] said to one of his men: “Say: ‘Yes, it is an appointment for both of us.’” [Ibn Hisham 2/94]
*http://www.witness-pioneer.org/vil/Books/SM_tsn/ch4s7.html
*The Quraish charged with full force, but the Muslims held fast. Then in the counter attack the Muslims broke the enemy line, and the Quraish fell back. At this stage the contingent of the Muslim archers, contrary to instructions, left their position in order to plunder the camp of the retreating Quraish. Khalid who was still a non-Muslim, and was fighting on the side of the Quraish rushed with his contingent and occupied the position vacated by the Muslim archers. The Quraish rallied, and launched an attack on the Muslims both from the front as well as the rear.
In the confusion that followed, many Muslims were martyred. Even the Holy Prophet was wounded seriously, and he fell in a pit where many of his followers lay dead. Thereupon a cry rose from the ranks of the enemy that they had killed the Prophet of Islam.
When the news of the Holy Prophet’s death got wind, panic seized some of the Muslims, and thinking that all was over, they fled to Madina According to tradition when Umar heard the news that the Holy Prophet had died, he flung his arms declaring that it was no use fighting any longer.
It is related that Anas b Nadar passing by Umar asked him how it had fared with the Prophet. Umar replied that he had heard that the Prophet had been killed. Anas observed that the Prophet’s death should not prevent him from fighting in the way of Allah, for Allah was alive. Saying this Anas rushed at the infidels, and was martyred after having received seventy wounds.
Later, the Holy Prophet was found lying in a pit. At this stage Ali, Abu Bakr, Umar, Talha, Zubair, and Harith gathered round the Prophet, and removed him to a place of safety.
Abu Sufiyan the leader of the Quraish climbed a hillock and shouted, “Is Muhammad there?” The Holy Prophet asked his companions to remain quiet.
Abu Sufiyan then called for Abu Bakr and Umar. No reply was made, and thereupon Abu Sufiyan shouted, “All of them have been killed.’
At this Umar could not restrain himself, and shouted in reply, “O enemy of Allah, all of us are alive.”
Abu Sufiyan in a mood of exultation cried, “Hubbal glory to thee.”
Umar retorted, "Only Allah is Most High and Great.”
Abu Sufiyan said, “We have Uzza with us, and you have no lord.”
Umar retaliated, “Allah is our Lord, and you have no lord.”
When the two armies withdrew from the battle-field, seventy Muslims lay dead on the battle-field. In the battle the Quraish had the upper hand. They felt satisfied that they had avenged their defeat at Badr. The Quraish were in no mood to press their advantage to march to Madina. They chose to return to Mecca.*http://www.facebook.com/note.php?note_id=220585094618158
