question #1 Sahih Muslim 209a, Book 1, Hadith 416 : What is the significance of intercession in Islam, particularly in relation to the afterlife?

Messenger of Allah, have you benefited Abu Talib in any way for he defended you and was fervent in your defence? The Messenger of Allah (may peace he upon him) said: Yes; he would be in the most shallow part of the Fire and were not for me, he would have been in the bottom-most depth of Hell.