Abu Hurairah relates: When (this verse) was revealed to him (the Holy Prophet), “And warn thy kindred,” the Messenger of Allah (peace and blessings of Allah be with him) said: “O people of Quraish, buy yourselves from Allah. I cannot avail you at all against Allah; O sons of Abd al-Muttalib, I cannot avail you at all against Allah; O Abbas bin Abd al-Muttalib, I cannot avail you at all against Allah; O Safiya (aunt of the Messenger of Allah), I cannot avail you at all against Allah; O Fatima, daughter of Muhammad, ask me whatever you like (in the world), but I cannot avail you at all against Allah (in the Hereafter).
(Sahih Muslim)
This hadīth reiterates the Islamic viewpoint on atonement, and categorically rejects it. One’s deeds will be judged in their face value and no relation with anyone howsoever high can come to his/her succour. Here “buy yourself from Allah” means to secure deliverance from Allah by doing good deeds. There are a number of ahadīth with regard to the intercession of the Holy Prophet (peace and blessings of Allah be with him) with the Lord for his Ummah.
It has also been made clear that intercession should not be taken in the sense of atonement. The Qur’an says: “No bearer of burdens shall be made to bear another’s burden.” (6:164) Intercession would be permitted explicitly at the Will of Allah and mere relationship with the Holy Prophet would not absolve anyone of his/her sins. No one can atone for the sins of others.