Surah Al-Baqarah, ayah 189

2:189

۞ يَسۡـَٔلُونَكَ عَنِ ٱلۡأَهِلَّةِۖ قُلۡ هِيَ مَوَٰقِيتُ لِلنَّاسِ وَٱلۡحَجِّۗ وَلَيۡسَ ٱلۡبِرُّ بِأَن تَأۡتُواْ ٱلۡبُيُوتَ مِن ظُهُورِهَا وَلَٰكِنَّ ٱلۡبِرَّ مَنِ ٱتَّقَىٰۗ وَأۡتُواْ ٱلۡبُيُوتَ مِنۡ أَبۡوَٰبِهَاۚ وَٱتَّقُواْ ٱللَّهَ لَعَلَّكُمۡ تُفۡلِحُونَ ١٨٩

Yas'alūnaka 'anil-ahillati qul hiya mawāqītu lin-nāsi wal-hajji walaysal-birru bi an ta'tul-buyūta min zuhūrihā walākinnal-birra manit-taqā wa tul-buyūta min abwābihā wattaqullāha la'allakum tuflihūn

They ask you, [O Muḥammad], about the crescent moons. Say, "They are measurements of time for the people and for ḥajj [pilgrimage]." And it is not righteousness to enter houses from the back, but righteousness is [in] one who fears Allāh. And enter houses from their doors. And fear Allāh that you may succeed.