AL ISRAA' — Ayat 12
وَجَعَلْنَا اللَّيْلَ وَالنَّهَارَ آيَتَيْنِ فَمَحَوْنَا آيَةَ اللَّيْلِ وَجَعَلْنَا آيَةَ النَّهَارِ مُبْصِرَةً لِتَبْتَغُواْ فَضْلاً مِّن رَّبِّكُمْ وَلِتَعْلَمُواْ عَدَدَ السِّنِينَ وَالْحِسَابَ وَكُلَّ شَيْءٍ فَصَّلْنَاهُ تَفْصِيلاً
And We have made the night and day two signs, and We erased the sign of the night and made the sign of the day visible that you may seek bounty from your Lord and may know the number of years and the account [of time]. And everything We have set out in detail.
Tafsir Ibnu Katsir
وَجَعَلْنَا الَّيْلَ وَالنَّهَارَ ءَايَتَيْنِ فَمَحَوْنَآ ءَايَةَ الَّيْلِ وَجَعَلْنَآ ءَايَةَ النَّهَارِ مُبْصِرَةً لِتَبْتَغُواْ فَضْلاً مِّن رَّبِّكُمْ وَلِتَعْلَمُواْ عَدَدَ السِّنِينَ وَالْحِسَابَ وَكُلَّ شَىْءٍ فَصَّلْنَاهُ تَفْصِيلاً
12. And We have appointed the night and the day as two Ayat (signs). Then, We have obliterated the sign of the night (with darkness) 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 to count (periods of time). And We have explained everything (in detail) with full explanation. Allah reminds us of the great signs that He created, including the alternation of the night and day, so that people may rest at night, and go out and earn a living, do their work, and travel during the day, and so that they may know the number of days, weeks, months and years, so they will know the appointed times for paying debts, doing acts of worship, dealing with transactions, paying rents and so on. Allah says: