Tafsir of As-Saffat 37:14

وإذا رأوا آية

And when they see an Ayah. means, clear evidence and proof,

يستسخرون

they mock at it. Mujahid and Qatadah said, "They make fun of it.''

وقالوا إن هذا إﻻ سحر مبين