• أَقْصَا
• قُصْوَىٰ
• قَصِيّ

Appears 5 times in the Quran.

1. 8:42 إِذْ أَنتُم بِٱلْعُدْوَةِ ٱلدُّنْيَا وَهُم بِٱلْعُدْوَةِ ٱلْقُصْوَىٰ وَٱلرَّكْبُ أَسْفَلَ مِنكُمْ وَلَوْ تَوَاعَدتُّمْ لَٱخْتَلَفْتُمْ فِى ٱلْمِيعَٰدِ وَلَٰكِن لِّيَقْضِىَ ٱللَّهُ أَمْرًا كَانَ مَفْعُولًا لِّيَهْلِكَ مَنْ هَلَكَ عَنۢ بَيِّنَةٍ وَيَحْيَىٰ مَنْ حَىَّ عَنۢ بَيِّنَةٍ وَإِنَّ ٱللَّهَ لَسَمِيعٌ عَلِيمٌ

   When you were on the nearer side (of the valley) and they were on the farthest side, while the caravan was in a lower place than you; and if you had mutually made an appointment, you would certainly have broken away from the appointment, but-- in order that Allah might bring about a matter which was to be done, that he who would perish might perish by clear proof, and he who would live might live by clear proof; and most surely Allah is Hearing, Knowing;
   

2. 17:1 سُبْحَٰنَ ٱلَّذِىٓ أَسْرَىٰ بِعَبْدِهِۦ لَيْلًا مِّنَ ٱلْمَسْجِدِ ٱلْحَرَامِ إِلَى ٱلْمَسْجِدِ ٱلْأَقْصَا ٱلَّذِى بَٰرَكْنَا حَوْلَهُۥ لِنُرِيَهُۥ مِنْ ءَايَٰتِنَآ إِنَّهُۥ هُوَ ٱلسَّمِيعُ ٱلْبَصِيرُ

   Glory be to Him Who made His servant to go on a night from the Sacred Mosque to the remote mosque of which We have blessed the precincts, so that We may show to him some of Our signs; surely He is the Hearing, the Seeing.
   

3. 19:22 فَحَمَلَتْهُ فَٱنتَبَذَتْ بِهِۦ مَكَانًا قَصِيًّا

   So she conceived him; then withdrew herself with him to a remote place.
   

4. 28:20 وَجَآءَ رَجُلٌ مِّنْ أَقْصَا ٱلْمَدِينَةِ يَسْعَىٰ قَالَ يَٰمُوسَىٰٓ إِنَّ ٱلْمَلَأَ يَأْتَمِرُونَ بِكَ لِيَقْتُلُوكَ فَٱخْرُجْ إِنِّى لَكَ مِنَ ٱلنَّٰصِحِينَ

   And a man came running from the remotest part of the city. He said: O Musa! surely the chiefs are consulting together to slay you, therefore depart (at once); surely I am of those who wish well to you.
   

5. 36:20 وَجَآءَ مِنْ أَقْصَا ٱلْمَدِينَةِ رَجُلٌ يَسْعَىٰ قَالَ يَٰقَوْمِ ٱتَّبِعُوا۟ ٱلْمُرْسَلِينَ

   And from the remote part of the city there came a man running, he said: O my people! follow the messengers;