The root خ م س (kh-m-s) in the Quran

بَلَىٰٓ إِن تَصْبِرُوا۟ وَتَتَّقُوا۟ وَيَأْتُوكُم مِّن فَوْرِهِمْ هَٰذَا يُمْدِدْكُمْ رَبُّكُم بِخَمْسَةِ ءَالَٰفٍ مِّنَ ٱلْمَلَٰٓئِكَةِ مُسَوِّمِينَ ۝١٢٥

Yes, if you remain patient and conscious of Allāh and they [i.e., the enemy] come upon you [attacking] in rage, your Lord will reinforce you with five thousand angels having marks [of distinction]."

وَٱعْلَمُوٓا۟ أَنَّمَا غَنِمْتُم مِّن شَىْءٍ فَأَنَّ لِلَّهِ خُمُسَهُۥ وَلِلرَّسُولِ وَلِذِى ٱلْقُرْبَىٰ وَٱلْيَتَٰمَىٰ وَٱلْمَسَٰكِينِ وَٱبْنِ ٱلسَّبِيلِ إِن كُنتُمْ ءَامَنتُم بِٱللَّهِ وَمَآ أَنزَلْنَا عَلَىٰ عَبْدِنَا يَوْمَ ٱلْفُرْقَانِ يَوْمَ ٱلْتَقَى ٱلْجَمْعَانِ وَٱللَّهُ عَلَىٰ كُلِّ شَىْءٍ قَدِيرٌ ۝٤١

And know that anything you obtain of war booty - then indeed, for Allāh is one fifth of it and for the Messenger and for [his] near relatives and the orphans, the needy, and the [stranded] traveler, if you have believed in Allāh and in that which We sent down to Our Servant on the day of criterion [i.e., decisive encounter] - the day when the two armies met [at Badr]. And Allāh, over all things, is competent.

سَيَقُولُونَ ثَلَٰثَةٌ رَّابِعُهُمْ كَلْبُهُمْ وَيَقُولُونَ خَمْسَةٌ سَادِسُهُمْ كَلْبُهُمْ رَجْمًۢا بِٱلْغَيْبِ وَيَقُولُونَ سَبْعَةٌ وَثَامِنُهُمْ كَلْبُهُمْ قُل رَّبِّىٓ أَعْلَمُ بِعِدَّتِهِم مَّا يَعْلَمُهُمْ إِلَّا قَلِيلٌ فَلَا تُمَارِ فِيهِمْ إِلَّا مِرَآءً ظَٰهِرًا وَلَا تَسْتَفْتِ فِيهِم مِّنْهُمْ أَحَدًا ۝٢٢

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."

وَٱلْخَٰمِسَةُ أَنَّ لَعْنَتَ ٱللَّهِ عَلَيْهِ إِن كَانَ مِنَ ٱلْكَٰذِبِينَ ۝٧

And the fifth [oath will be] that the curse of Allāh be upon him if he should be of the liars.

وَٱلْخَٰمِسَةَ أَنَّ غَضَبَ ٱللَّهِ عَلَيْهَآ إِن كَانَ مِنَ ٱلصَّٰدِقِينَ ۝٩

And the fifth [oath will be] that the wrath of Allāh be upon her if he was of the truthful.

وَلَقَدْ أَرْسَلْنَا نُوحًا إِلَىٰ قَوْمِهِۦ فَلَبِثَ فِيهِمْ أَلْفَ سَنَةٍ إِلَّا خَمْسِينَ عَامًا فَأَخَذَهُمُ ٱلطُّوفَانُ وَهُمْ ظَٰلِمُونَ ۝١٤

And We certainly sent Noah to his people, and he remained among them a thousand years minus fifty years, and the flood seized them while they were wrongdoers.

أَلَمْ تَرَ أَنَّ ٱللَّهَ يَعْلَمُ مَا فِى ٱلسَّمَٰوَٰتِ وَمَا فِى ٱلْأَرْضِ مَا يَكُونُ مِن نَّجْوَىٰ ثَلَٰثَةٍ إِلَّا هُوَ رَابِعُهُمْ وَلَا خَمْسَةٍ إِلَّا هُوَ سَادِسُهُمْ وَلَآ أَدْنَىٰ مِن ذَٰلِكَ وَلَآ أَكْثَرَ إِلَّا هُوَ مَعَهُمْ أَيْنَ مَا كَانُوا۟ ثُمَّ يُنَبِّئُهُم بِمَا عَمِلُوا۟ يَوْمَ ٱلْقِيَٰمَةِ إِنَّ ٱللَّهَ بِكُلِّ شَىْءٍ عَلِيمٌ ۝٧

Have you not considered that Allāh knows what is in the heavens and what is on the earth? There are not three in a private conversation but that He is the fourth of them, nor are there five but that He is the sixth of them - and no less than that and no more except that He is with them [in knowledge] wherever they are. Then He will inform them of what they did on the Day of Resurrection. Indeed Allāh is, of all things, Knowing.

تَعْرُجُ ٱلْمَلَٰٓئِكَةُ وَٱلرُّوحُ إِلَيْهِ فِى يَوْمٍ كَانَ مِقْدَارُهُۥ خَمْسِينَ أَلْفَ سَنَةٍ ۝٤

The angels and the Spirit [i.e., Gabriel] will ascend to Him during a Day the extent of which is fifty thousand years.