Musnad Ahmad 21
It was narrated that Yazeed bin Abi Sufyan said:
Abu Bakr said, when he sent me to Syria: O Yazeed, you have relatives and you may give them precedence in allocating positions of authority; that is the most serious thing I fear for you, because the Messenger of Allah (ﷺ) said: `Whoever is appointed in charge of any affairs of the Muslims and appoints over them anyone by way of favouritism, the curse of Allah be upon him and Allah will not accept any obligatory or nafl prayer from him until he admits him to Hell. And whoever allows anyone to transgress the sacred limits set by Allah has transgressed the sacred limits of Allah unlawfully, and on him will be the curse of Allah and Allah will forsake him.`
حَدَّثَنَا يَزِيدُ بْنُ عَبْدِ رَبِّهِ، قَالَ حَدَّثَنَا بَقِيَّةُ بْنُ الْوَلِيدِ، قَالَ حَدَّثَنِي شَيْخٌ، مِنْ قُرَيْشٍ عَنْ رَجَاءِ بْنِ حَيْوَةَ، عَنْ جُنَادَةَ بْنِ أَبِي أُمَيَّةَ، عَنْ يَزِيدَ بْنِ أَبِي سُفْيَانَ، قَالَ قَالَ أَبُو بَكْرٍ رَضِيَ اللَّهُ عَنْهُ حِينَ بَعَثَنِي إِلَى الشَّامِ يَا يَزِيدُ إِنَّ لَكَ قَرَابَةً عَسَيْتَ أَنْ تُؤْثِرَهُمْ بِالْإِمَارَةِ وَذَلِكَ أَكْبَرُ مَا أَخَافُ عَلَيْكَ فَإِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ مَنْ وَلِيَ مِنْ أَمْرِ الْمُسْلِمِينَ شَيْئًا فَأَمَّرَ عَلَيْهِمْ أَحَدًا مُحَابَاةً فَعَلَيْهِ لَعْنَةُ اللَّهِ لَا يَقْبَلُ اللَّهُ مِنْهُ صَرْفًا وَلَا عَدْلًا حَتَّى يُدْخِلَهُ جَهَنَّمَ وَمَنْ أَعْطَى أَحَدًا حِمَى اللَّهِ فَقَدْ انْتَهَكَ فِي حِمَى اللَّهِ شَيْئًا بِغَيْرِ حَقِّهِ فَعَلَيْهِ لَعْنَةُ اللَّهِ أَوْ قَالَ تَبَرَّأَتْ مِنْهُ ذِمَّةُ اللَّهِ عَزَّ وَجَلَّ‏.‏