The Quran root ر ب ع r-b-ʿ

لِّلَّذِينَ يُؤْلُونَ مِن نِّسَائِهِمْ تَرَبُّصُ أَرْبَعَةِ أَشْهُرٍ فَإِن فَاءُوا فَإِنَّ اللَّهَ غَفُورٌ رَّحِيمٌ ٢٢٦

أَرْبَعَةِ arbaʿati · four

For those who swear not to have sexual relations with their wives is a waiting time of four months, but if they return [to normal relations] - then indeed, Allāh is Forgiving and Merciful. (Surah Al-Baqarah, 2:226)

وَالَّذِينَ يُتَوَفَّوْنَ مِنكُمْ وَيَذَرُونَ أَزْوَاجًا يَتَرَبَّصْنَ بِأَنفُسِهِنَّ أَرْبَعَةَ أَشْهُرٍ وَعَشْرًا فَإِذَا بَلَغْنَ أَجَلَهُنَّ فَلَا جُنَاحَ عَلَيْكُمْ فِيمَا فَعَلْنَ فِي أَنفُسِهِنَّ بِالْمَعْرُوفِ وَاللَّهُ بِمَا تَعْمَلُونَ خَبِيرٌ ٢٣٤

أَرْبَعَةَ arbaʿata · (for) four

And those who are taken in death among you and leave wives behind - they, [the wives, shall] wait four months and ten [days]. And when they have fulfilled their term, then there is no blame upon you for what they do with themselves in an acceptable manner. And Allāh is [fully] Aware of what you do. (Surah Al-Baqarah, 2:234)

وَإِذْ وَاعَدْنَا مُوسَىٰ أَرْبَعِينَ لَيْلَةً ثُمَّ اتَّخَذْتُمُ الْعِجْلَ مِن بَعْدِهِ وَأَنتُمْ ظَالِمُونَ ٥١

أَرْبَعِينَ arbaʿīna · forty

And [recall] when We made an appointment with Moses for forty nights. Then you took [for worship] the calf after him [i.e., his departure], while you were wrongdoers. (Surah Al-Baqarah, 2:51)

وَإِنْ خِفْتُمْ أَلَّا تُقْسِطُوا فِي الْيَتَامَىٰ فَانكِحُوا مَا طَابَ لَكُم مِّنَ النِّسَاءِ مَثْنَىٰ وَثُلَاثَ وَرُبَاعَ فَإِنْ خِفْتُمْ أَلَّا تَعْدِلُوا فَوَاحِدَةً أَوْ مَا مَلَكَتْ أَيْمَانُكُمْ ذَٰلِكَ أَدْنَىٰ أَلَّا تَعُولُوا ٣

وَرُبَاعَ warubāʿa · or four

And if you fear that you will not deal justly with the orphan girls, then marry those that please you of [other] women, two or three or four. But if you fear that you will not be just, then [marry only] one or those your right hands possess [i.e., slaves]. That is more suitable that you may not incline [to injustice]. (Surah An-Nisa, 4:3)

وَلَكُمْ نِصْفُ مَا تَرَكَ أَزْوَاجُكُمْ إِن لَّمْ يَكُن لَّهُنَّ وَلَدٌ فَإِن كَانَ لَهُنَّ وَلَدٌ فَلَكُمُ الرُّبُعُ مِمَّا تَرَكْنَ مِن بَعْدِ وَصِيَّةٍ يُوصِينَ بِهَا أَوْ دَيْنٍ وَلَهُنَّ الرُّبُعُ مِمَّا تَرَكْتُمْ إِن لَّمْ يَكُن لَّكُمْ وَلَدٌ فَإِن كَانَ لَكُمْ وَلَدٌ فَلَهُنَّ الثُّمُنُ مِمَّا تَرَكْتُم مِّن بَعْدِ وَصِيَّةٍ تُوصُونَ بِهَا أَوْ دَيْنٍ وَإِن كَانَ رَجُلٌ يُورَثُ كَلَالَةً أَوِ امْرَأَةٌ وَلَهُ أَخٌ أَوْ أُخْتٌ فَلِكُلِّ وَاحِدٍ مِّنْهُمَا السُّدُسُ فَإِن كَانُوا أَكْثَرَ مِن ذَٰلِكَ فَهُمْ شُرَكَاءُ فِي الثُّلُثِ مِن بَعْدِ وَصِيَّةٍ يُوصَىٰ بِهَا أَوْ دَيْنٍ غَيْرَ مُضَارٍّ وَصِيَّةً مِّنَ اللَّهِ وَاللَّهُ عَلِيمٌ حَلِيمٌ ١٢

الرُّبُعُ l-rubuʿu · (is) the fourth

And for you is half of what your wives leave if they have no child. But if they have a child, for you is one fourth of what they leave, after any bequest they [may have] made or debt. And for them [i.e., the wives] is one fourth if you leave no child. But if you leave a child, then for them is an eighth of what you leave, after any bequest you [may have] made or debt. And if a man or woman leaves neither ascendants nor descendants but has a brother or a sister, then for each one of them is a sixth. But if they are more than two, they share a third, after any bequest which was made or debt, as long as there is no detriment [caused]. [This is] an ordinance from Allāh, and Allāh is Knowing and Forbearing. (Surah An-Nisa, 4:12)

سَيَقُولُونَ ثَلَاثَةٌ رَّابِعُهُمْ كَلْبُهُمْ وَيَقُولُونَ خَمْسَةٌ سَادِسُهُمْ كَلْبُهُمْ رَجْمًا بِالْغَيْبِ وَيَقُولُونَ سَبْعَةٌ وَثَامِنُهُمْ كَلْبُهُمْ قُل رَّبِّي أَعْلَمُ بِعِدَّتِهِم مَّا يَعْلَمُهُمْ إِلَّا قَلِيلٌ فَلَا تُمَارِ فِيهِمْ إِلَّا مِرَاءً ظَاهِرًا وَلَا تَسْتَفْتِ فِيهِم مِّنْهُمْ أَحَدًا ٢٢

رَّابِعُهُمْ rābiʿuhum · the forth of them

They [i.e., people] will say there were three, the fourth of them being their dog; and they will say there were five, the sixth of them being their dog - guessing at the unseen; and they will say there were seven, and the eighth of them was their dog. Say, [O Muḥammad], "My Lord is most knowing of their number. None knows them except a few. So do not argue about them except with an obvious argument and do not inquire about them among [the speculators] from anyone." (Surah Al-Kahf, 18:22)