It is narrated from Sayyiduna Mu'adh bin Anas al-Juhani (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever teaches some knowledge will continue to receive its reward as long as anyone who acts upon it continues to act upon it, and nothing is reduced from the reward of the one who acts upon it."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17580