Those companions of Muḥammad - the peace and blessing of Allāh be upon him and his descendants - who were the custodians (of divine messages) know that I never disobeyed Allāh or His Messenger  - the peace and blessing of Allāh be upon him and his descendants - at all, and by virtue of the courage  with which Allāh honoured me I supported him with my life on occasions when even the brave turned away and feet remained behind (instead of proceeding forward).
When the Prophet - the peace and blessing of Allāh be upon him and his descendants - died his head was on my chest, and his (last) breath blew over my palms and I passed it over my face. I performed his (funeral) ablution, may Allāh bless him and his descendants, and the angels helped me. The house and the courtyard were full of them. One party of them was descending and the other was ascending. My ears continually caught their humming voice, as they invoked Allāh’s blessing on him, till we buried him in his grave.
Thus, who can have greater rights with him than I during his life or after his death? Therefore depend on your intelligence and make your intentions pure in fighting your enemy, because I swear by Him who is such that there is no god but He, that I am on the path of truth and that they (the enemy) are on the misleading path of wrong. You hear what I say; and I seek Allāh’s forgiveness for myself and for you.
 Ibn Abi’l-Ḥadīd has written (in Sharḥ Nahj al-balāghah, vol. 10, pp. 180-183) that Amīr al-mu’minīn’s saying that he never disobeyed the commands of the Prophet is a sort of taunt to those who felt no hesitation in rejecting the Prophet’s commands and sometimes even checked him. For example, when, at the time of the peace of al-Ḥudaybiyah, the Prophet was agreeable to negotiate peace with the unbelievers among the Quraysh, Umar became so enraged that he expressed doubts about the prophethood of the Prophet whereupon Abu Bakr had to say: Woe be to you! Keep clinging to him. He is certainly Allāh’s Messenger and He will not ruin him.
The introduction to the oath, ‘inna’, and the word of emphasis ‘lam’ which are used here to create conviction about the prophethood shows that the addressee had gone farther than mere doubt, because these words of emphasis are employed only when the stage of denial has been reached. However, if belief required absence of doubt, the presence of doubt must imply defect in the belief, as Allāh says: The believers are only those who believe in Allāh and His Messenger, they doubt not thereafter,... (Qur’ān, 49:15)
Similarly, when the Prophet intended to say the funeral prayers of Ubayy ibn Salūl the same companion (Umar) said to him, “How do you intend to seek forgiveness for this Chief of hypocrites?” And he even drew away the Prophet by catching the skirt (of his shirt). Then the Prophet had to say, “No act of mine is beside the command of Allāh”. In the same way the Prophet’s command to accompany the force of Usāmah ibn Zayd was ignored. The greatest of all these insolences was displayed in connection with the Prophet’s intention to write down his advice as to when such a blame was laid against the Prophet which proves an absence of belief in the commands of the sharī‘ah, and creates a doubt about each command as to whether it is based on divine revelation or (Allāh may forbid) just the result of mental disorder.
 Who can deny that the ever-successful lion of Allāh, ‘Alī ibn Abī Ṭālib (a.s.) shielded the Prophet on every critical occasion and performed the duty of protecting him by dint of the courage and valour gifted to him by Allāh. The first occasion of risking his life was when the unbelievers from the Quraysh decided finally to kill the Prophet and ‘Alī slept on his bed surrounded by enemies and under the direct peril of swords, whereby the enemies were not able to succeed in their aims. Then, in those battles where the enemies used to attack the Prophet together and where the feet of even the reputed heroes could not stand firm, Amīr al-mu’minīn remained steadfast with the banner (of Islam) in his hand. Ibn ‘Abd al-Barr and al-Ḥākim writes about it:
Ibn ‘Abbās says that ‘Alī had four qualities which no one else possessed. Firstly, he was the first among Arabs and non-Arabs to have said prayers with the Messenger of Allāh. Secondly, he always had the banner of Islam in his hand in every battle. Thirdly, when people ran away from the Prophet, ‘Alī remained with him; and fourthly it was he who gave the Prophet his funeral ablution and laid him in his grave. (al-Istī‘ab, vol. 3, p. 1090; al-Mustadrak ‘alā aṣ-ṣaḥīḥayn, vol. 3, p. 111)
A study of the holy wars of Islam fought in the Prophet’s days leaves no doubt that, except for the battle of Tabūk in which Amīr al-mu’minīn did not partake, all other battles bear testimony to his fine performance and all the successes are due to his valour. Thus, in the battle of Badr seventy unbelievers were killed, half of whom were killed by ‘Alī’s sword. In the battle of Uḥud, when victory changed into defeat as a result of the Muslims engaging themselves in the collection of booty, and they fled away under the sudden attack of the enemy, Amīr al-mu’minīn remained steadfast, taking jihād to be a religious obligation, and displayed such conspicuous performance in support and defence of the Prophet that the Prophet too acknowledged it and also the Angel. Again, in the battle of the Trench (al-Khandaq), the Prophet was accompanied by three thousand combatants, but none dared face ‘Amr ibn ‘Abdawadd. At last, Amīr al-mu’minīn killed him and saved the Muslims from ignominy. In the battle of Ḥunayn, the Muslims were proud of their number because they were ten thousand while the unbelievers were only four thousand, but here too they leapt onto the booty, as a consequence of which the unbelievers gained the opportunity, and pounced upon them. Bewildered with this sudden attack the Muslims fled away as the Holy Qur’ān says:
Most certainly did Allāh help you in many (battle) fields, and on the day of Ḥunayn, when made you vain your great number, but they availed you nothing, and was straitened the earth against you with all its extensiveness, then ye turned back in retreat. (9:25)
On this occasion also, Amīr al-mu’minīn was steady like a rock, and eventually with Allāh’s, support, victory was achieved.