Tafsir of Ar-Rahman 55:17

This is the predicate of an omitted subject, meaning: "He is the Lord of..." or "The One who performed what has been mentioned of these wondrous deeds is the Lord of the sun's two rising points in summer and winter, and its two setting points." This is in accordance with what a group has transmitted from Ibn Abbas. It is also narrated from Mujahid, Qatada, and Ikrimah that "the two Easts" are the rising point of winter and the rising point of summer, and "the two Wests" are the setting point of winter and the setting point of summer, without explicit mention of the sun.

It has also been said: The two Easts are the rising point of dawn and the rising point of the sun, and the two Wests are the setting point of the sun and the setting point of the twilight. Abu Hayyan reported something similar regarding the two Wests, and regarding the two Easts, he suggested they are the point where dawn emerges and the point where the sun emerges. However, the relied-upon view, held by the majority, is that they refer to the two rising points and two setting points of summer and winter. A consequence of this is that He, Glory be to Him, is the Lord of all existents between them.

It has also been said that "The Lord" is a subject, and its predicate is His saying, "He released..." but this is not strong.

Abu Haywah and Ibn Abi Ablah read it as Rabbi (in the genitive case), as an appositive (badal) to "your Lord" [mentioned previously].