An-Nisa: 51
Al-Jibt: The idols and everything worshipped other than Allah.
The reason for this revelation is that Huyayy ibn Akhtab and Ka'b ibn al-Ashraf—both Jews—went out to Mecca with a group of Jews to form an alliance with the Quraysh to fight the Messenger of Allah (peace be upon him). The Quraysh said to them, "You are People of the Book, and you are closer to Muhammad than we are, so we do not trust your treachery. Prostrate yourselves to our idols so that we may trust you." They did so.
"They believe in Al-Jibt and At-Taghut"
This is because they prostrated to the idols and obeyed Iblis in what they did.
Abu Sufyan asked them, "Are we better guided, or is Muhammad?"
Ka'b asked, "What does Muhammad say?"
They replied, "He commands the worship of Allah alone and forbids polytheism."
Ka'b asked, "And what is your religion?"
They replied, "We are the guardians of the House (the Ka'bah), we provide water for the pilgrims, we host the guests, and we ransom the captives." They listed their deeds, and he said, "You are better guided."