Tafsir of Ash-Shu`ara' 26:187

فٲسقط علينا كسفا من السماء

So cause a piece of the heaven to fall on us, Ad-Dahhak said: "One side of the heavens.'' Qatadah said: "A piece of the heaven.'' As-Suddi said: "A punishment from heaven.'' This is like what the Quraysh said, as Allah tells us:

وقالوا لن نومن لك حتى تفجر لنا من اﻻرض ينبوعا

And they say: "We shall not believe in you, until you cause a spring to gush forth from the earth for us, until:

أو تسقط السماء كما زعمت علينا كسفا أو تٲتى بالله والمليكة قبيﻼ

Or you cause the heaven to fall upon us in pieces, as you have pretended, or you bring Allah and the angels before (us) face to face.'' (17:90-92)

وإذ قالوا اللهم إن كان هذا هو الحق من عندك فٲمطر علينا حجارة من السماء

And (remember) when they said: "O Allah! If this is indeed the truth from You, then rain down stones on us from the sky....'' (8:32) Similarly, these ignorant disbelievers said:

فٲسقط علينا كسفا من السماء إن كنت من الصادقين

So, cause a piece of the heaven to fall on us, if you are of the truthful!

قال ربي أعلم بما تعملون