Sayyiduna Mu'adh bin Jabal (may Allah be pleased with him) said: I was riding behind the Prophet (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: "His right upon them is that they worship Him and do not associate anything with Him." Then he said: "Do you know what their right upon Him is if they do that?" I said: Allah and His Messenger know best. He (peace and blessings be upon him) said: "Their right is that He does not punish them."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17409