No entry in Lane's Arabic-English Lexicon for the root ق س و. Lane (d. 1876) died before completing the lexicon, and its later volumes are thin or absent — this root falls in that gap. Its absence here means only that Lane has no article for it, not that it has no meaning.
The roots that most often share a verse with ق س و. Window: the verse. Measure: the number of distinct verses in which both roots occur (of the 6 this root appears in). Ubiquitous roots are excluded so genuinely connected concepts surface — see the method.
Page 1 of 1. The root is highlighted in each verse.
ثُمَّقَسَتْقُلُوبُكُممِّنۢبَعْدِذَٰلِكَفَهِىَكَٱلْحِجَارَةِأَوْأَشَدُّقَسْوَةًوَإِنَّمِنَٱلْحِجَارَةِلَمَايَتَفَجَّرُمِنْهُٱلْأَنْهَٰرُوَإِنَّمِنْهَالَمَايَشَّقَّقُفَيَخْرُجُمِنْهُٱلْمَآءُوَإِنَّمِنْهَالَمَايَهْبِطُمِنْخَشْيَةِٱللَّهِوَمَاٱللَّهُبِغَٰفِلٍعَمَّاتَعْمَلُونَ
Reference 2:74فَبِمَانَقْضِهِممِّيثَٰقَهُمْلَعَنَّٰهُمْوَجَعَلْنَاقُلُوبَهُمْقَٰسِيَةًيُحَرِّفُونَٱلْكَلِمَعَنمَّوَاضِعِهِۦوَنَسُوا۟حَظًّامِّمَّاذُكِّرُوا۟بِهِۦوَلَاتَزَالُتَطَّلِعُعَلَىٰخَآئِنَةٍمِّنْهُمْإِلَّاقَلِيلًامِّنْهُمْفَٱعْفُعَنْهُمْوَٱصْفَحْإِنَّٱللَّهَيُحِبُّٱلْمُحْسِنِينَ
Reference 5:13فَلَوْلَآإِذْجَآءَهُمبَأْسُنَاتَضَرَّعُوا۟وَلَٰكِنقَسَتْقُلُوبُهُمْوَزَيَّنَلَهُمُٱلشَّيْطَٰنُمَاكَانُوا۟يَعْمَلُونَ
Reference 6:43لِّيَجْعَلَمَايُلْقِىٱلشَّيْطَٰنُفِتْنَةًلِّلَّذِينَفِىقُلُوبِهِممَّرَضٌوَٱلْقَاسِيَةِقُلُوبُهُمْوَإِنَّٱلظَّٰلِمِينَلَفِىشِقَاقٍۭبَعِيدٍ
Reference 22:53أَفَمَنشَرَحَٱللَّهُصَدْرَهُۥلِلْإِسْلَٰمِفَهُوَعَلَىٰنُورٍمِّنرَّبِّهِۦفَوَيْلٌلِّلْقَٰسِيَةِقُلُوبُهُممِّنذِكْرِٱللَّهِأُو۟لَٰٓئِكَفِىضَلَٰلٍمُّبِينٍ
Reference 39:22أَلَمْيَأْنِلِلَّذِينَءَامَنُوٓا۟أَنتَخْشَعَقُلُوبُهُمْلِذِكْرِٱللَّهِوَمَانَزَلَمِنَٱلْحَقِّوَلَايَكُونُوا۟كَٱلَّذِينَأُوتُوا۟ٱلْكِتَٰبَمِنقَبْلُفَطَالَعَلَيْهِمُٱلْأَمَدُفَقَسَتْقُلُوبُهُمْوَكَثِيرٌمِّنْهُمْفَٰسِقُونَ
Reference 57:16No published investigation cites this root yet. When one does, it appears here — the evidence links back to the argument.