وَكَائِنْ تَرَى مِنْ صَامِتٍ لَكَ مُعْجِبٍ ۞ زِيَادَتُهُ أَوْ نَقْصُهُ فِي التَّكَلُّمِ
How many a silent person impresses you, yet speaking reveals whether his worth increases or diminishes.
Kāʾin here expresses multiplicity: how many people! Ṣāmit is a silent person, while al-takallum means speaking. The paired opposites “increase or decrease” describe the change in one’s estimate of the person once words reveal their understanding, restraint, or lack of these qualities.