Kitaab At-Tawheed, Chapter: 16
The Words of Allah , Most High:
" Verily, you will not guide everyone whom you love, but Allah guides whom He wills and He knows best those who Will guided" (Qur'an 28:56)
Allah informs the Prophet 
that his assiduous pursuit of his uncle, Abu Talib in order to call him to Islam will be of no avail, that he will not be guided; for Allah knows all things - past, present and future, and none other than Allah has knowledge of the unseen. And He informs His Messenger that successful guidance comes only by His will, and He makes successful the guidance for whosoever of His slaves He Wills and that is because He knows best who deserves to be guided to success.
Benefits Derived From This Verse
1. That successful guidance comes only through Allah.
2. That the natural love of a person for his disbelieving kin - so long as they do not fight against Islam - does not conflict with true faith and belief.
3. Confirmation of Allah's Divine Attribute of Will.
The Relevance of This Verse to the Subject of the Chapter
That the verse proves that there can be no successful guidance through the Prophet alone in spite of the fact that he is the noblest of all mankind; and if he cannot guide anyone of his own Will, then obviously, no lesser human being can do so.
The Relevance of This Verse to the Subject of Tawheed
That the verse proves that successful guidance comes only from Allah and therefore seeking it from other than Allah is of Shirk.
Important Note
There is no contradiction between this verse and the Words of Allah , Most High:
" And verily, you do guide [men] to the Straight Path" (Qur'an 42:52)
For in the former verse, Allah is negating the ability of the Prophet to make people accept his guidance, while in the latter He says that His Messenger Calls people to the Straight Path.
..ooOOoo..
It is authentically reported on the authority of Ibn Al-Musyyib from his father, that he said: "When death approached Abu Talib, Allah's Messenger came to him, and with him were `Abdullah Ibn Abi Umayyah and Abu Jahl. The Prophet said to his uncle: "Oh uncle! Say: Laa ilaaha illallaah, a word by which I will plead for you with Allah ." But they said: "Will you reject the faith of `Abdul Muttalib?" And the Messenger of Allah repeated his words, and again they repeated their question, and so the last testament of Abu Talib was that he reamined upon the religion of `Abdul Muttalib and he refused to say: Laa ilaaha illallaah. So the Messenger of Allah said: "Verily, I will continue to ask forgiveness for you until I am forbidden to do so." Then Allah revealed:
" It is not for the Prophet or those who believe with him to ask forgiveness for the polytheists, even though they be their close relative after it has been made plain to them that they are of the people of the Hell-fire" (Qur'an 9:113)
And concerning Abu Talib, He revealed: " Verily, you will not guide everyone whom you love, but Allah guides whom He wills and He knows best those who will be guided" 1
Sa'eed Ibn Al-Musayyib (ra) informs us in this Hadith, that when death approached Abu Talib, the Prophet requested him to pronounce the words of Tawheed (i.e. Laa ilaaha Iilallaah) so that he might be a witness for him to Allah ; but Abu Talib's two wicked visitors aroused in him the passion of the Jahiliyyah, reminding him that it was the religion of his ancestors, and so Abu Talib refused to embrace Islam an died upon the religion of his people, after which the Prophet said that he would continue to ask forgiveness for him until Allah forbade him to do so. This he did, until Allah revealed the above-mentioned verse.
Benefits Derived From This Hadith
1. The permissibility of visiting the sick, even though he may be a polytheist if the purpose in so doing is the desire to call him to Islam.
2. That whoever said: Laa ilaaha illallaah at the time of death, will be judged by appearances to be a Muslim, even though he may never have done any good deeds or acts of worship in Islam.
3. That the most important deeds are one's final in life.
4. The obligation to strive in the cause of propagating Islam, to be patient and persevering in that cause, and to order the good and forbid the evil.
5. Refutation of the claim of those who assert that `Abdul Muttalib and his forebears were Muslims.
6. The harm inflicted by the evil people upon the good.
7. The forbiddance of seeking forgiveness from Allah for the disbelievers and polytheists, even though they be close family members and even though they might perform services for Islam and the Muslims.
Relevance of This Hadith to the Subject of the Chapter
That the Hadith proves the negation of successful guidance through the Prophet and since he is the noblest of mankind, it stands to reason that no lesser mortal may be assured of successful guidance.
Relevance of This Hadith to the Subject of Tawheed
That it proves that successful guidance is from Allah , Alone and therefore seeking it from other than Him is an act of Shirk.
Footnotes