"…And bravery is defined by two things:
a) the strength and firmness of the heart in the face of fears, and
b) physical strength when fighting, such that one can kill with immense force and magnitude.
The first is the definition of bravery. As for the latter, it indicates physical strength and ability, and not everyone who possesses physical strength has strength of heart, and vice versa.
Because of this, you may find that it is said regarding a man who kills many people: 'He would do this if he had with him those who could guarantee his safety.' But, if he becomes scared, he is stricken with cowardice, and his heart becomes detached. And you would find the man with a firm heart who has not killed many people with his own hands firm in the face of fears, going forth in the face of hardships, and this is a characteristic that is required by the commanders, leaders, and forerunners of war, more so than the other, as the forerunner, if he is brave and firm at heart, will go forth and remain firm and will not be defeated, and his supporters will fight alongside him. If he was a coward and weak at heart, he will be humiliated, will not go forth, and will not remain firm, even if he is physically strong.
And the Prophet was the most complete in regards to this bravery that is appropriate for the commanders in war, and he did not kill with his hand anyone except Ubayy bin Khalaf. He killed him on the day of Uhud, and did not kill anyone else with his hand before or after this."
['Minhaj as-Sunnah an-Nabawiyyah'; 8/78]
The Two Sahihs recorded that Sa`d bin Abi Waqqas said, "On the day of Uhud, I saw two men wearing white clothes, one to the right of the Prophet and one to his left, who were defending the Prophet fiercely. I have never seen these men before or after that day.'' Meaning angels Jibril and Mika'il, peace be upon them.
Abu Al-Aswad said that, `Urwah bin Az-Zubayr said, "Ubayy bin Khalaf of Bani Jumah swore in Makkah that he would kill the Messenger of Allah . When the Messenger was told of his vow, he said, `Rather, I shall kill him, Allah willing.' On the day of Uhud, Ubayy came while wearing iron shields and proclaiming, `May I not be saved, if Muhammad is saved.' He then headed to the direction of the Messenger of Allah intending to kill him, but Mus`ab bin `Umayr, from Bani Abd Ad-Dar, intercepted him and shielded the Prophet with his body, and Mus`ab bin `Umayr was killed. The Messenger of Allah saw Ubayy's neck exposed between the shields and helmet, stabbed him with his spear, and Ubayy fell from his horse to the ground. However, no blood spilled from his wound. His people came and carried him away while he was moaning like an ox. They said to him, `Why are you so anxious, it is only a flesh wound' Ubayy mentioned to them the Prophet's vow, `Rather, I shall kill Ubayy', then commented, `By He in Whose Hand is my soul! If what hit me hits the people of Dhul-Majaz (a popular pre-Islamic marketplace), they would all have perished.' He then died and went to the Fire,
[فَسُحْقًا لاًّصْحَـبِ السَّعِيرِ]
(So, away with the dwellers of the blazing Fire!) [67:11].''This was collected by Musa bin `Uqbah from Az-Zuhri from Sa`id bin Al-Musayyib.
Surah 'Aal Imraan - tafsir ibn Kathir;
Muhammadur Rasulullah. P.362-3.
Syed Abul Hasan Ali Hasani Nadwi,
The number of his battles was 27 while he is reported to have sent out 46 forays and expeditions [Estimate by Ibn al Qayim in Za'ad al Ma'ad] - although no fighting had taken place in many of them. (within a period of 10 years - the Medinan Period after alot of patience against torture in Makkah [torture lasted for around 13 years in Makkah].)
Never in the history of human conflict had any conqueror shed so little blood and was crowned with such a remarkable success. In all these battles, only 1018 persons, Muslims aswell as non-Muslims lost their lives. (Qazi Muhammad Sulaiman Mansurpuri gives this figure after a detailed study [Rahmatulil 'Alamin]...
Such was the public tranquility and orderliness resulting from the Prophets campaigns, that a rider would go from San'a to Hadramout [in Yemen where continuous tribal warfare was common] without fearing anyone, except Allah and the wolf who might trouble his sheep... [Bukhari Volume 9, Book 85 [ikrah - (saying something under compulsion)], Number 76.]
Another report says that the women from Qadisiyya [in iraq] went alone on their camels for pilgrimage to Makkah without the least anxiety or fear. [Ibn Hisham, Vol.2, p.581]
This was a country in which, from the time immemorial, fights and forays, battles between nomadic tribes and raids on one anothers flocks and property had been accepted unquestionably as a part of the desert life. Even the caravans of neighbouring powerful kingdoms [Byzantine Romans, Sassanid Persians] dared not cross the country (of Arabia) in pre-Islamic days without powerful escorts and guides...
And, how successful were these campaigns of the Prophet can be judged from the fact that within a brief period of ten years, more than a million square miles was won for Islam: the Islamic state expanded at an average rate of some 274 square miles daily at the cost of one martyr a month. [Brig. Gulzar Ahmed, The Battles of the Prophet of Allah, Karachi , p.28].
This respect for human blood is unequaled in the annals of man [Prophet Muhammad brought the most benefit - with the least amount of casualties]. The truth of this assertion is simply borne out if the losses of these campaigns are placed by the side of casualties in the last two world wars... yet none of these two blood-stained wars can be claimed to have done any good to the humanity nor did they solve any problem of the world. The Inquisitions established by the Roman catholic church in the Middle Ages for trial and punishment for heretics is reported to have taken a toll of 12 million lives. [John Devenport, Apology for Muhammad and Qur'an].