إِذَا رَأَيْتَهُمْ حَسِبْتَهُمْ لُؤْلُؤًا مَنْثُورًا.
When you see them, you would take them for scattered pearls.
Qurʾan 76:19 uses “hasibtahum” to describe a viewer’s impression: the scene evokes the beauty and sparkling distribution of scattered pearls. “Luʾluʾan manthuran” is the image through which the scene is depicted.
The individuals are not literally pearls. The comparison evokes appropriate features such as brightness, delicacy and their distributed arrangement, creating a vivid sensory image.