Tafsir of Az-Zukhruf 43:64

(Indeed, Allah is my Lord and your Lord, so worship Him) This is an explanation of what He commanded them to obey Him in, which is the belief in monotheism and the worship through [adherence to] the religious laws.

(This) meaning this monotheism and worship through the religious laws, (is a straight path) that does not lead its traveler astray. It is either a continuation of the speech of Jesus, peace be upon him, or an initiation of speech from Allah the Exalted, affirming the statement of Jesus, peace be upon him.