The Quran root ر ب ص r-b-ṣ

وَالْمُطَلَّقَاتُ يَتَرَبَّصْنَ بِأَنفُسِهِنَّ ثَلَاثَةَ قُرُوءٍ وَلَا يَحِلُّ لَهُنَّ أَن يَكْتُمْنَ مَا خَلَقَ اللَّهُ فِي أَرْحَامِهِنَّ إِن كُنَّ يُؤْمِنَّ بِاللَّهِ وَالْيَوْمِ الْآخِرِ وَبُعُولَتُهُنَّ أَحَقُّ بِرَدِّهِنَّ فِي ذَٰلِكَ إِنْ أَرَادُوا إِصْلَاحًا وَلَهُنَّ مِثْلُ الَّذِي عَلَيْهِنَّ بِالْمَعْرُوفِ وَلِلرِّجَالِ عَلَيْهِنَّ دَرَجَةٌ وَاللَّهُ عَزِيزٌ حَكِيمٌ ٢٢٨

يَتَرَبَّصْنَ yatarabbaṣna · shall wait

Divorced women remain in waiting [i.e., do not remarry] for three periods, and it is not lawful for them to conceal what Allāh has created in their wombs if they believe in Allāh and the Last Day. And their husbands have more right to take them back in this [period] if they want reconciliation. And due to them [i.e., the wives] is similar to what is expected of them, according to what is reasonable. But the men [i.e., husbands] have a degree over them [in responsibility and authority]. And Allāh is Exalted in Might and Wise. (Surah Al-Baqarah, 2:228)

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

يَتَرَبَّصْنَ yatarabbaṣna · (the widows) should wait

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)

قُلْ هَلْ تَرَبَّصُونَ بِنَا إِلَّا إِحْدَى الْحُسْنَيَيْنِ وَنَحْنُ نَتَرَبَّصُ بِكُمْ أَن يُصِيبَكُمُ اللَّهُ بِعَذَابٍ مِّنْ عِندِهِ أَوْ بِأَيْدِينَا فَتَرَبَّصُوا إِنَّا مَعَكُم مُّتَرَبِّصُونَ ٥٢

مُّتَرَبِّصُونَ mutarabbiṣūna · (are) waiting

Say, "Do you await for us except one of the two best things [i.e., martyrdom or victory] while we await for you that Allāh will afflict you with punishment from Himself or at our hands? So wait; indeed we, along with you, are waiting." (Surah At-Tawbah, 9:52)

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

تَرَبُّصُ tarabbuṣu · (is a) waiting (of)

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)