Ibn Abbas reported: The Messenger of Allah, peace and blessings be upon him, addressed the people during the farewell sermon, saying, “Satan has despaired that he will ever be worshiped in your lands. Rather, he is pleased for you to obey him in matters beside that, among your deeds you consider insignificant. Beware, O people! Verily, I have left among you what you must hold firmly to, for you will never be led astray again: the Book of Allah and the Sunnah of His Prophet. Verily, a Muslim is the brother of another Muslim, and the Muslims are brothers. It is not lawful for a man to take the wealth of his brother, unless he gives it freely and willingly. You may not wrong each other. Do not turn back to the ways of unbelievers after me, striking the necks of each other.”
Source: al-Mustadrak 289
Grade: Sahih (authentic) according to Al-Albani
عَنِ ابْنِ عَبَّاسٍ أَنّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ خَطَبَ النَّاسَ فِي حَجَّةِ الْوَدَاعِ فَقَالَ قَدْ يَئِسَ الشَّيْطَانُ بِأَنْ يُعْبَدَ بِأَرْضِكُمْ وَلَكِنَّهُ رَضِيَ أَنْ يُطَاعَ فِيمَا سِوَى ذَلِكَ مِمَّا تُحَاقِرُونَ مِنْ أَعْمَالِكُمْ فَاحْذَرُوا يَا أَيُّهَا النَّاسُ إِنِّي قَدْ تَرَكْتُ فِيكُمْ مَا إِنِ اعْتَصَمْتُمْ بِهِ فَلَنْ تَضِلُّوا أَبَدًا كِتَابَ اللَّهِ وَسُنَّةَ نَبِيِّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِنَّ كُلَّ مُسْلِمٍ أَخُو الْمُسْلِمِ الْمُسْلِمُونَ إِخْوَةٌ وَلا يَحِلُّ لامْرِئٍ مِنْ مَالِ أَخِيهِ إِلا مَا أَعْطَاهُ عَنْ طِيبِ نَفْسٍ وَلا تَظْلِمُوا وَلا تَرْجِعُوا مِنْ بَعْدِي كُفَّارًا يَضْرِبُ بَعْضُكُمْ رِقَابَ بَعْضٍ
289 المستدرك على الصحيحين
40 المحدث الألباني خلاصة حكم المحدث صحيح في صحيح الترغيب