قُحَاحُ أَمْرٍ

The root, foundation, origin, or source, of a thing or an affair; its essence, or very essence; or what is, or constitutes, its most essential, or elementary, part; the ultimate element to which it can be reduced or resolved; its utmost point or particular; or its principal, or best, part; synonym أَصْلُهُ (Kr, L, K, TA) and فَصُّهُ (K, TA) and خَالِصُهُ. (L, K, TA.) One says, صَارَ إِلَى قُحَاحِ الأَمْرِ He reached, or arrived at, the root, &c., of the affair. (L.) And لَقَد وَقَعْتُ بِقُحَاحِ قُرِّكَ, as also وَقَعْتُ بِقُرِّكَ, I have become acquainted with (عَلِمْتُ) all that thou knowest, nothing thereof being hidden from me. (Ibn-Buzurj, TA.) And لَأَضْطَرَّنَّكَ إِلى قُحَاحِكَ I will assuredly make thee to have recourse to thine utmost effort, or endeavour, i. e. إِلَى جَهْدِكَ: or, as IAar says, لا ضطرّنّك الى تُرِّكَ وَقُحَاحِكَ, i. e. إِلَى أَصْلِكَ. (L. [See أَصْلٌ.])

See also قُحٌّ, latter half.