Musnad Ahmad 1034:50

Wahb ibn Jarir narrated to us, Hisham ibn Hassan narrated to us, from Muhammad, from Abu Ubaydah ibn Hudhayfah, from Hudhayfah, who said: A man asked [for charity] during the time of the Prophet, may God bless him and grant him peace, and the people refrained. Then, a man gave him [something], and the people [subsequently] gave. The Prophet, may God bless him and grant him peace, said: "Whoever initiates a good practice and it is followed, he shall have his reward and the rewards of those who follow him, without their rewards being diminished in the slightest. And whoever initiates an evil practice and it is followed, he shall bear his burden and the burdens of those who follow him, without their burdens being diminished in the slightest."