It is narrated from Maqatil that Hadrat Abu Talib (a.s.) made a will to Bani Hashim at the time of his death - 'O Bani Hashim, if you all obey the Prophet (peace be upon him and his household) and if you all believe in his truthfulness you will be guided.'
In Midarajan Nabuwwah (of Mohaddisse Dehalvi) and in Rauzatus Safa vol. 2 the following sermon of Hadrat Abu Talib (a.s.) addressing the people, which also served as his will, has been recorded.
'O Quraish! You are the most pious servants of Allah. I recommend Muhammad (peace be upon him and his household) to you in matters of righteousness and virtue. He is the trusted one of Quraish and the truthful one of Arabia and he possesses all the virtues for which I am making a will to you. He(peace be upon him and his household) has brought such good news, which has been accepted by your hearts, but your tongue has chosen to deny it on account of fear of taunts. On the contrary, I see that the weak and the defenseless have accepted his (peace be upon him and his household) invitation and have testified in his Shariat and revere him. Thus they have become the leaders and your chiefs have been humiliated. The proud ones have been humbled and the humble ones have become self-sufficient. Those who distanced themselves from him (peace be upon him and his household) are the unfortunate ones. I can see that the people of Arabia are attached to him (peace be upon him and his household) and have expanded their hearts for his love and have very dutifully and diligently prepared themselves to follow him and serve him. O Quraish! Befriend Muhammad (peace be upon him and his household) and supporters of his group. I swear by Allah those people who do not tread the path shown by him (peace be upon him and his household) will not find guidance, and only they will accept and adhere to his ways and qualities who are virtuous. If death could have been delayed and there would have been some more time left in my life, I would be helping him and as far as possible I would have repelled all dangers from his path.'
Alas! Hadrat Abu Talib's (a.s.) last wish was not fulfilled and death did not spare him for a moment. The Quraish rejected the friendly advice given to them by Hadrat Abu Talib (a.s.) and left (a.s.) and walked out angrily. After some time this great helper of Islam answered the call of His Lord and returned to Him. Now Islam was devoid of the shelter of this generous helper who for 50 years had undertaken the responsibility of protecting and safeguarding the Prophet of Islam (peace be upon him and his household). He had taken all the blows on himself, which the polytheists and opponents of Islam had tried to inflict by their taunts and actions. Even in his old age he was enthusiastic in contributing for the progress and propagation of Islam.