وَجَعَلْنَا الَّيْلَ وَالنَّهَارَ ءَايَتَيْنِ فَمَحَوْنَآ ءَايَةَ الَّيْلِ وَجَعَلْنَآ ءَايَةَ النَّهَارِ مُبْصِرَةً لِتَبْتَغُواْ فَضْلاً مِّن رَّبِّكُمْ وَلِتَعْلَمُواْ عَدَدَ السِّنِينَ وَالْحِسَابَ وَكُلَّ شَىْءٍ فَصَّلْنَاهُ تَفْصِيلاً
(And We have appointed the night and the day as two Ayat (signs). Then, We have obliterated the sign of the night while We have made the sign of the day illuminating, that you may seek bounty from your Lord, and that you may know the number of the years and the reckoning. And We have explained everything with full explanation.) (17:12) So, He has given the sun its own light, and the moon its (reflection of) light, and has given each its own orbit. So the sun rises each day and sets at the end of the day, giving one kind of light all the time, but it moves, rising and setting at different points in the summer and winter, thus making the days and nights longer or shorter alternatively according to the season. Its authority is in the daytime, for it is the heavenly body that dominates the day. As for the moon, Allah has decreed that it should pass through different phases. At the beginning of the month, the moon appears small when it rises. It gives off little light, then on the second night its light increases and it rises to a higher position, and the higher it rises the more light it gives -- even though it is reflected from the sun -- until it becomes full on the fourteenth night of the month. Then it starts to wane until the end of the month, until it appears like the old dried curved date stalk. Ibn `Abbas, may Allah be pleased with him, said, â€This is the original stem (which connects the bunch of dates to the tree).'' The Arabs have a name for each set of three nights in a month, according to the phases of the moon. They call the first three nights Ghurar; the next three nights Nufal; the next three nights Tusa` (nine) -- because the last of them is the ninth. The next three nights are called `Ushar (ten) -- because the first of them is the tenth. The next three nights are called Al-Bid (white) -- because of the light of the moon which shines brightly throughout these three nights. The next three nights are called Dura`, the plural of Dar`a', because on the first of them the night is dark from the moon rising late. Dar`a' refers to the black sheep, i.e., the one whose head is black; the next three nights Zulam; then Hanadis, then Da'adi; then Mihaq, because of the absence of moonlight at the beginning of the month. Abu `Ubayd did not recognize the names Tusa` and `Ushar, in the book Gharib Al-Musannaf.