Sayyiduna Hudhayfah (may Allah be pleased with him) states: I was riding behind the Prophet (peace and blessings be upon him) on a mount. He (peace and blessings be upon him) said: O Hudhayfah! Do you know what the right of Allah Almighty over the servants is? I said: Allah and His Messenger know best. The Prophet (peace and blessings be upon him) said: That they (the servants) worship Him and do not associate anyone with Him as a partner. Then he said: O Hudhayfah! I said: Here I am, O Messenger of Allah! The Prophet (peace and blessings be upon him) said: Do you know what their right over Allah Almighty will be when the servants do that? I said: Allah and His Messenger know best. The Prophet (peace and blessings be upon him) said: That He forgives them.
Imam al-Bazzar recorded it, and its narrators are thiqat (trustworthy). The narrator Simak bin al-Walid is a Tabi'i and thiqah (trustworthy), but I do not know whether he heard from Sayyiduna Hudhayfah (may Allah be pleased with him) or not.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الإيمان / 150