"When Abu Talib was dying, the Prophet came to him and found Abu Jahl and 'Abdullah bin Abi Umayyah with him. He said: 'O uncle, say La ilaha illallah(there is none worthy of worship except Allah), a word with which I will defend you before Allah.' Abu Jahl and 'Abdullah bin Abi Umayyah said: 'O Abu Talib, are you turning away from the religion of 'Abdul-Muttalib.' Then the Prophet said: 'I will keep on asking for Allah's forgiveness for you unless I am forbidden to do so.' Then the following was revealed: It is not (proper) for the Prophet and those who believe to ask Allah's forgiveness for the idolaters. And the following was revealed: Verily, you (O Muhammad) guide not whom you like." (Using translation from Nasāʾī 2035)  

لَمَّا حَضَرَتْ أَبَا طَالِبٍ الْوَفَاةُ دَخَلَ عَلَيْهِ رَسُولُ اللهِ ﷺ وَعِنْدَهُ أَبُو جَهْلٍ وَعَبْدُ اللهِ بْنُ أَبِي أُمَيَّةَ فَقَالَ أَيْ عَمِّ قُلْ لَا إِلَهَ إِلَّا اللهُ كَلِمَةً أُحَاجُّ لَكَ بِهَا عِنْدَ اللهِ فَقَالَ لَهُ أَبُو جَهْلٍ وَعَبْدُ اللهِ بْنُ أَبِي أُمَيَّةَ يَا أَبَا طَالِبٍ أَتَرْغَبُ عَنْ مِلَّةِ عَبْدِ الْمُطَّلِبِ فَلَمْ يَزَالَا يُكَلِّمَانِهِ حَتَّى قَالَ آخِرَ شَيْءٍ كَلَّمَهُمْ بِهِ هُوَ عَلَى مِلَّةِ عَبْدِ الْمُطَّلِبِ فَقَالَ النَّبِيُّ ﷺ لَأَسْتَغْفِرَنَّ لَكَ مَا لَمْ أُنْهَ عَنْكَ فَنَزَلَتْ {مَا كَانَ لِلنَّبِيِّ وَالَّذِينَ آمَنُوا أَنْ يَسْتَغْفِرُوا لِلْمُشْرِكِينَ} [التوبة 113] وَنَزَلَتْ {إِنَّكَ لَا تَهْدِي مَنْ أَحْبَبْتَ وَلَكِنَّ اللهَ يَهْدِي مَنْ يَشَاءُ} [القصص 56]  

"I heard a man praying for forgiveness for his parents who were idolaters, and I said: 'Are you praying for forgiveness for them even though they are idolators?" He said: 'Didn't Ibrahim pray for forgiveness for his father?' I went to the Prophet and told him about that, then the following revealed: And Ibrahim's (Abraham) invoking (of Allah) for his father's forgiveness was only because of a promise he (Ibrahim) had made to him (his father)." (Daif) (Using translation from Nasāʾī 2036)  

سَمِعْتُ رَجُلًا يَسْتَغْفِرُ لِأَبَوَيْهِ وَهُمَا مُشْرِكَانِ فَقُلْتُ أَتَسْتَغْفِرُ لَهُمَا وَهُمَا مُشْرِكَانِ؟ فَقَالَ أَوَلَمْ يَسْتَغْفِرْ إِبْرَاهِيمُ لِأَبِيهِ فَأَتَيْتُ النَّبِيَّ ﷺ فَذَكَرْتُ ذَلِكَ لَهُ فَنَزَلَتْ {وَمَا كَانَ اسْتِغْفَارُ إِبْرَاهِيمَ لِأَبِيهِ إِلَّا عَنْ مَوْعِدَةٍ وَعَدَهَا إِيَّاهُ} [التوبة 114]