Al-Aswad bin Hilal (may Allah have mercy on him) narrates from Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) that he said: I was riding behind the Messenger of Allah (peace and blessings be upon him), and he (peace and blessings be upon him) said to me: "O Mu'adh, do you know what the right of Allah upon His servants is?" I said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "That they worship Him and do not associate anything with Him." Then he said to me: "O Mu'adh, and what is the right of the servants upon Allah if they do that?" I said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "That He does not punish them."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17453