It was said: رَّ‌بُّ السَّمَاوَاتِ وَالْأَرْ‌ضِ وَمَا بَيْنَهُمَا وَرَ‌بُّ الْمَشَارِ‌قِ (the Lord of the heavens and the earth and what is between them, and Lord of the points of the sunrise. - 37:5). Now, a Being to whom goes the credit of having created and sustained such a mind-boggling range of creations has to be the One most deserving of ownership. And this entire universe is a positive proof of His existence and Oneness. The word: الْمَشَارِ‌قِ (al-mashariq) as used here is the plural form of مَشرِق mashriq or East. Since, the sun rises from a new point every day of the year, therefore, its orientations in the East are many, and it is on this basis that the plural form has been employed here.