At-Tawba 9:31

They have taken their rabbis and monks as lords[29] besides Allah, as well as the Messiah, son of Mary, even though they were commanded to worship only One God; none has the right to be worshiped except Him, glorified is He far above what they associate with Him[30].

[29] By obeying them rather than obeying Allah’s commandments.
[30] ‘Adiyy ibn Hātim al-Tā’iyy (رضي الله عنه), who was Christian before embracing Islam, narrated that he came to the Messenger (ﷺ) while he was reciting this verse, and he said to the Messenger: “We do not worship them!” He asked: “Do they not deem unlawful what Allah allowed and you follow them making it unlawful, and declare lawful what Allah forbade and you follow them making it lawful?” ‘Adiyy said: “Indeed!” then he (ﷺ) said: “That is their worship!” [At-Tirmidhī: 3095; also see: Matthew 15:1-9, Isaiah 29:13, Jeremiah 8:8]

They have taken their scholars and monks as lords besides Allāh,[467] and [also] the Messiah, the son of Mary.[468] And they were not commanded except to worship one God; there is no deity except Him. Exalted is He above whatever they associate with Him.

[467] By their obedience to them rather than to what Allāh ordained.
[468] By their worship of him in conjunction with Allāh.

31. They (Jews and Christians) took their rabbis and their monks to be their lords besides Allâh (by obeying them in things which they made lawful or unlawful according to their own desires without being ordered by Allâh), and (they also took as their Lord) Messiah, son of Maryam (Mary), while they (Jews and Christians) were commanded [in the Taurât (Torah) and the Injeel (Gospel)] to worship none but One Ilâh (God - Allâh) Lâ ilâha illa Huwa (none has the right to be worshipped but He)[8]. Praise and glory be to Him (far above is He) from having the partners they associate (with Him)."

[8] (V.9:31) Once while Allâh’s Messenger صلى الله عليه وسلم was reciting this Verse, ‘Adi bin Hâtim said, "O Allâh’s Messenger! They do not worship them (i.e. the rabbis and monks)." Allâh’s Messenger صلى الله عليه وسلم said: "They certainly do. [They (i.e. the rabbis and monks) made lawful things as unlawful and unlawful things as lawful, and they (i.e. Jews and Christians) followed them; and by doing so, they really worshipped them]." (Narrated by Ahmad, At-Tirmidhi, and Ibn Jarîr).

They have taken as lords beside Allah their rabbis and their monks and the Messiah son of Mary, when they were bidden to worship only One Allah. There is no Allah save Him. Be He Glorified from all that they ascribe as partner (unto Him)!