Jareer bin Abdullah reported,

Some bedouins came to the Messenger of Allah ﷺ wearing woolen garments. He saw their poor condition and that need had befallen them, so he urged the people to give in charity. They were slow to respond, until that could be seen on his face.Then a man from the Ansar came with a pouch of silver, then another came, and then they followed one after another, until joy could be seen on his face.The Messenger of Allah ﷺ said, "Whoever introduces a good practice in Islam that is acted upon after him will have recorded for him a reward like that of those who act upon it, without diminishing anything from their rewards. And whoever introduces an evil practice in Islam that is acted upon after him will have recorded against him a burden like that of those who act upon it, without diminishing anything from their burdens."

Muslim 6800

Sahih

حدثني زهير بن حرب حدثنا جرير بن عبد الحميد عن الأعمش عن موسى بن عبد الله بن يزيد وأبي الضحى عن عبد الرحمن بن هلال العبسي

عن جرير بن عبد الله قال

جاء ناس من الأعراب إلى رسول الله ﷺ عليهم الصوف فرأى سوء حالهم قد أصابتهم حاجة فحث الناس على الصدقة فأبطئوا عنه حتى رئي ذلك في وجهه قال ثم إن رجلا من الأنصار جاء بصرة من ورق ثم جاء آخر ثم تتابعوا حتى عرف السرور في وجهه فقال رسول الله ﷺ من سن في الإسلام سنة حسنة فعمل بها بعده كتب له مثل أجر من عمل بها ولا ينقص من أجورهم شيء ومن سن في الإسلام سنة سيئة فعمل بها بعده كتب عليه مثل وزر من عمل بها ولا ينقص من أوزارهم شيء

مسلم 6800صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Knowledge
Chapter
Whoever establishes a good or bad practice, and whoever calls to guidance or misguidance
Numbering
Darussalam 6800
Muslim 6800