رَبُّهُم

رَبُّهُم is a phrase (شِبْهُ الجُمْلَةِ), a compound consisting of a possessed noun and a possessive noun

PhraseNoun / NounNounNoun
شِبْهُ الجُمْلَةِمُضَافٌ وَ مُضَافٌ إِلَيْهِمُضَافٌ إِلَيْهِمُضَافٌ
PhrasePossessive compoundPossessive noun/ownerNoun possessed/owned
Lord of theirsرَبُّهُم=هُم+رَبُّ
their Lordtheirsthe Lord of
Surah/Below are the 11 verses in the holy Quran containing the compoundرَبُّهُم
Verse
So, their Lord responded to them, “Indeed I will not let go to waste deeds of the doerفَاسْتَجَابَ لَهُمْ رَبُّهُم أَنِّي لَآ أُضِيْعُ عَمَلَ عَامِلٍ
among you from male or female, each of you from otherمِنْكُمْ مِنْ ذَكَرٍ أَوْ أُنْثَى بَعْضُكُم مِّنْ بَعْضٍ
so, those who emigrated and were driven out from their homesفَالَّذِيْنَ هَاجَرُوا وَأُخْرِجُوا مِنْ دَيَارِهِمْ
and were harmed in My way and fought and were killed,وَأُوْذُوا فِي سَبِيْلِي وَقَاتَلُوا وَقُتِلُوا
I will certainly remove from them their evil deedsلَأُكَفِّرَنَّ عَنْهُمْ سَيِّئَاتِهِمْ 
and surely, I will admit them into gardens, rivers flowing from underneath themوَلَأُدْخِلَنَّهُمْ جَنَّاتٍ تَجْرِي مِنْ تَحْتِهَا الأَنْهَارُ
3-195a reward from Allah (SWT) and Allah (SWT) with Him is the best reward”ثَوَابًا مِنْ عِنْدِ اللهِ وَاللهُ عِنْدَهُ حُسْنُ الثَّوَابِ
their Lord gives them glad tidings of mercy from Him and approval and gardensيُبَشِّرُهُمْ رَبُّهُم بِرَحْمَةٍ مِّنْهُ وَرِضْوَانٍ وَجَنَّاتٍ
9-21for them, in it enduring (favors) blissلَّهُمْ فِيْهَا نَعِيْمٌ مُّقِيْمٌ
Indeed, those who believe and do righteous deeds, their Lord guides themإِنَّ الَّذِيْنَ ءَامَنُوا وَعَمِلُوا الصَّالِحَاتِ يَهْدِيْهِمْ رَبُّهُم
10-9by their faith, rivers flow from underneath them in the gardens of delightبِإِيْمَانِهِمْ تَجْرِي مِنْ تَحْتِهِمُ الأَنْهَارُ فِي جَنَّاتِ النَّعِيْمِ 
14-13 
18-21 
45-30 
51-16 
52-18 
72-10 
upon them green garments of fine silk and brocadeعَالِيَهُمْ ثِيَابُ سُنْدُسٍ خُضْرٌ وَإِسْتَبْرَقٌ
and they will be adorned with bracelets of silverوَحُلُّوا أَسَاوِرَ مِنْ فِضَّةٍ
76-21and their Lord will give them to drink a purifying drinkوَسَقَاهُمْ رَبُّهُم شَرَابًا طَهُوْرًا
however, they denied him and killed itفَكَذَّبُوْهُ فَعَقَرُوْهَا
so, their Lord destroyed them due to their sinفَدَمْدَمَ عَلَيْهِم رَبُّهُم بِذَنْبِهِمْ
91-14and made them equal in destructionفَسَوَّاهَا