(Al-Muzammil) 73 : 9
رَبُّ الْمَشْرِقِ وَالْمَغْرِبِ لَا إِلَٰهَ إِلَّا هُوَ فَاتَّخِذْهُ وَكِيلًا
The Lord of the east and west, there is no Deity besides He, so you select Him as Authority.
See explanation 2: 115; 39: 62; and 64: 12-13.