Tafsir of Ash-Shu`ara' 26:187

"Then cause to fall upon us fragments (kisafan)..."

It is recited as kisfan with a sukun (on the sin) and with a vowel (kasra), and both are plurals of kisfa, like qita' (pieces) and sidr. It is said that al-kisf and al-kisfa are like al-ri' and al-ri'a, meaning a piece. To kasafa something means to cut it.

"The sky" here refers to the clouds or the canopy (the firmament). Their request for this was only due to their persistence in denial and disbelief. Had there been in them the slightest inclination toward belief, they would not have even let it cross their minds, let alone requested it.

The meaning is: "If you are truthful that you are a prophet, then call upon Allah to cause fragments of the sky to fall upon us."

{ He said, "My Lord is most knowing of what you do." }