Mundhir b. Jarir reported on the authority of his father:
While we were in the company of the Messenger of Allah (ﷺ) in the early hours of the morning, some people came there (who) were barefooted, naked, wearing striped woollen clothes, or cloaks, with their swords hung (around their necks). Most of them, nay, all of them, belonged to the tribe of Mudar. The colour of the face of the Messenger of Allah (ﷺ) underwent a change when he saw them in poverty. He then entered (his house) and came out and commanded Bilal (to pronounce Adhan). He pronounced Adhan and Iqima, and he (the Prophet) observed prayer (along with his Companion) and then addressed (them reciting verses of the Holy Qur'an): '" 0 people, fear your Lord, Who created you from a single being" to the end of the verse," Allah is ever a Watcher over you" (iv. 1). (He then recited) a verse of Sura Hashr:" Fear Allah. and let every soul consider that which it sends forth for the morrow and fear Allah" (lix. 18). (Then the audience began to vie with one another in giving charity.) Some donated a dinar, others a dirham, still others clothes, some donated a sa' of wheat, some a sa' of dates; till he (the Prophet) said: (Bring) even if it is half a date. Then a person from among the Ansar came there with a money bag which his hands could scarcely lift; in fact, they could not (lift). Then the people followed continuously, till I saw two heaps of eatables and clothes, and I saw the face of the Messenger (ﷺ) glistening, like gold (on account of joy). The Messenger of Allah (ﷺ) said: He who sets a good precedent in Islam, there is a reward for him for this (act of goodness) and reward of that also who acted according to it subsequently, without any deduction from their rewards; and he who sets in Islam an evil precedent, there is upon him the burden of that, and the burden of him also who acted upon it subsequently, without any deduction from their burden.
حَدَّثَنِي مُحَمَّدُ بْنُ الْمُثَنَّى الْعَنَزِيُّ، أَخْبَرَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ عَوْنِ، بْنِ أَبِي جُحَيْفَةَ عَنِ الْمُنْذِرِ بْنِ جَرِيرٍ، عَنْ أَبِيهِ، قَالَ كُنَّا عِنْدَ رَسُولِ اللَّهِ صلى الله عليه وسلم فِي صَدْرِ النَّهَارِ قَالَ فَجَاءَهُ قَوْمٌ حُفَاةٌ عُرَاةٌ مُجْتَابِي النِّمَارِ أَوِ الْعَبَاءِ مُتَقَلِّدِي السُّيُوفِ عَامَّتُهُمْ مِنْ مُضَرَ بَلْ كُلُّهُمْ مِنْ مُضَرَ فَتَمَعَّرَ وَجْهُ رَسُولِ اللَّهِ صلى الله عليه وسلم لِمَا رَأَى بِهِمْ مِنَ الْفَاقَةِ فَدَخَلَ ثُمَّ خَرَجَ فَأَمَرَ بِلاَلاً فَأَذَّنَ وَأَقَامَ فَصَلَّى ثُمَّ خَطَبَ فَقَالَ " { يَا أَيُّهَا النَّاسُ اتَّقُوا رَبَّكُمُ الَّذِي خَلَقَكُمْ مِنْ نَفْسٍ وَاحِدَةٍ} إِلَى آخِرِ الآيَةِ { إِنَّ اللَّهَ كَانَ عَلَيْكُمْ رَقِيبًا} وَالآيَةَ الَّتِي فِي الْحَشْرِ { اتَّقُوا اللَّهَ وَلْتَنْظُرْ نَفْسٌ مَا قَدَّمَتْ لِغَدٍ وَاتَّقُوا اللَّهَ} تَصَدَّقَ رَجُلٌ مِنْ دِينَارِهِ مِنْ دِرْهَمِهِ مِنْ ثَوْبِهِ مِنْ صَاعِ بُرِّهِ مِنْ صَاعِ تَمْرِهِ - حَتَّى قَالَ - وَلَوْ بِشِقِّ تَمْرَةٍ " . قَالَ فَجَاءَ رَجُلٌ مِنَ الأَنْصَارِ بِصُرَّةٍ كَادَتْ كَفُّهُ تَعْجِزُ عَنْهَا بَلْ قَدْ عَجَزَتْ - قَالَ - ثُمَّ تَتَابَعَ النَّاسُ حَتَّى رَأَيْتُ كَوْمَيْنِ مِنْ طَعَامٍ وَثِيَابٍ حَتَّى رَأَيْتُ وَجْهَ رَسُولِ اللَّهِ صلى الله عليه وسلم يَتَهَلَّلُ كَأَنَّهُ مُذْهَبَةٌ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ سَنَّ فِي الإِسْلاَمِ سُنَّةً حَسَنَةً فَلَهُ أَجْرُهَا وَأَجْرُ مَنْ عَمِلَ بِهَا بَعْدَهُ مِنْ غَيْرِ أَنْ يَنْقُصَ مِنْ أُجُورِهِمْ شَىْءٌ وَمَنْ سَنَّ فِي الإِسْلاَمِ سُنَّةً سَيِّئَةً كَانَ عَلَيْهِ وِزْرُهَا وَوِزْرُ مَنْ عَمِلَ بِهَا مِنْ بَعْدِهِ مِنْ غَيْرِ أَنْ يَنْقُصَ مِنْ أَوْزَارِهِمْ شَىْءٌ " .