Mishkat al-Masabih 2659
Abu Bakra said that the Prophet gave them the following sermon on the day of sacrifice:
“Time has completed a cycle to the form of the day when God created the heavens and the earth. The year contains twelve months of which four are sacred, three of them consecutive, viz. Dhul Qa'da, Dhul Hijja. and Muharram, and also Rajab of Mudar which comes between Jumada and Sha'ban.”( The month Rajab is here connected with the North Arabian tribe of Mudar because they are said to have honoured it greatly and never to have broken its sacred nature. The precise reference to its place among the months is said’to be for the purpose of removing any doubt about it owing to the earlier practice of periodically intercalating a month) He asked, “What month is this?" and when the people replied that God and His messenger knew best, he remained silent so that they thought he would give it a new name, but he said, “Is it not Dhul Hijja?" and they replied that it was. He asked, “What town is this?" and when the people replied that God and His apostle knew best, he remained silent so that they thought he would give it a new name, but he said, “Is it not al-Balda?”( This word occurs a number of times in the Qur’an in the general sense of a district, but in 27, 91 it is used particularly of Mecca which is there called “this district (balda)". In the tradition the word seems to be used as if it were a proper name) and they replied that it was. He asked, “What day is this?” and when the people replied that God and His messenger knew best, he remained silent so that they thought he would give it a new name, but he said, “Is it not the day of sacrifice?" and they replied that it was. He said, “Your lives, property and honour must be regarded by you with a sacredness like that of this day of yours in this town of yours in this month of yours. You will meet your Lord, and He will ask you about your deeds. O, do not revert after my death to being people who are astray, beheading one another. Have I delivered the message ?" When they replied that he had he said, “O God, testify ; and let him who is present convey it to him who is absent, for many a one to whom a message is conveyed has a more retentive memory than the one who hears.” 

Bukhari and Muslim.
عَنْ أَبِي بَكْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: خَطَبَنَا النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَوْمَ النَّحْرِ قَالَ: «إِنَّ الزَّمَانَ قَدِ اسْتَدَارَ كَهَيْئَتِهِ يَوْمَ خَلَقَ اللَّهُ السَّمَاوَاتِ وَالْأَرْضَ السَّنَةُ اثْنَا عَشَرَ شَهْرًا مِنْهَا أَرْبَعَةٌ حُرُمٌ ثَلَاثٌ مُتَوَالِيَاتٌ ذُو الْقَعْدَةِ وَذُو الْحِجَّةِ وَالْمُحَرَّمُ وَرَجَبُ مُضَرَ الَّذِي بَيْنَ جُمَادَى وَشَعْبَانَ» وَقَالَ: «أَيُّ شَهْرٍ هَذَا؟» قُلْنَا: اللَّهُ وَرَسُولُهُ أَعْلَمُ فَسَكَتَ حَتَّى ظَنَنَّا أَنَّهُ سَيُسَمِّيهِ بِغَيْرِ اسْمِهِ فَقَالَ: «أَلَيْسَ ذَا الْحِجَّةِ؟» قُلْنَا: بَلَى. قَالَ: «أَيُّ بَلَدٍ هَذَا؟» قُلْنَا: اللَّهُ وَرَسُولُهُ أَعْلَمُ فَسَكَتَ حَتَّى ظَنَنَّا أَنَّهُ سَيُسَمِّيهِ بِغَيْرِ اسْمِهِ قَالَ: «أَلَيْسَ الْبَلْدَةَ؟» قُلْنَا: بَلَى قَالَ «فَأَيُّ يَوْمٍ هَذَا؟» قُلْنَا: اللَّهُ وَرَسُولُهُ أَعْلَمُ فَسَكَتَ حَتَّى ظَنَنَّا أَنَّهُ سَيُسَمِّيهِ بِغَيْرِ اسْمِهِ. قَالَ: «أَلَيْسَ يَوْمَ النَّحْرِ؟» قُلْنَا: بَلَى. قَالَ: «فَإِنَّ دِمَاءَكُمْ وَأَمْوَالَكُمْ وَأَعْرَاضَكُمْ عَلَيْكُمْ حَرَامٌ كَحُرْمَةِ يَوْمِكُمْ هَذَا فِي بَلَدِكُمْ هَذَا فِي شَهْرِكُمْ هَذَا وَسَتَلْقَوْنَ رَبَّكُمْ فَيَسْأَلُكُمْ عَنْ أَعْمَالِكُمْ أَلَا فَلَا تَرْجِعُوا بِعْدِي ضُلَّالًا يَضْرِبُ بَعْضُكُمْ رِقَابَ بَعْضٍ أَلَا هَلْ بَلَّغْتُ؟» قَالُوا: نَعَمْ. قَالَ: «اللَّهُمَّ اشْهَدْ فَلْيُبَلِّغِ الشَّاهِدُ الْغَائِبَ فَرُبَّ مُبَلَّغٍ أَوْعَى مِنْ سَامِعٍ»