«قُلْ هَلْ يَسْتَوِي الَّذِينَ يَعْلَمُونَ وَالَّذِينَ لَا يَعْلَمُونَ» (al-Zumar 39:9)
Say: Are those who know equal to those who do not know?
Neither “yaʿlamūn” nor “lā yaʿlamūn” has an expressed object. The contrast is not between knowing and not knowing one named item; it concerns the standing of those characterized by knowledge and those lacking it.
Assuming an unmentioned object such as “this particular subject” would narrow the claim. The objectless expression preserves its broad contrast and illustrates disregarding any particular object.