Al-Kashshaf: Al-Hadid (57:21)
{سابقوا}
Hasten, with the haste of those competing against their peers on the racetrack, toward a Paradise {عرضها كعرض السماء والارض} (its width is like the width of the heaven and the earth).
Al-Suddi said: "Like the width of the seven heavens and the seven earths."
The width is mentioned rather than the length because, for anything possessing both width and length, the width is less than the length. Thus, when its width is described as vast, it is understood that its length is even more vast and extended. It is also possible that "width" here is intended to mean "vastness," as in the Almighty’s saying: {فذو دعاء عريض} (then he is full of extensive/broad supplication) [Fussilat: 51].
When He belittled the world and diminished its significance, and magnified the affair of the Hereafter, He urged His servants to hasten toward attaining what He promised of it: namely, the forgiveness that saves from severe punishment, and the triumph of entering Paradise.
{ذلك}
That which is promised of forgiveness and Paradise.
{يؤتيه من يشاء}
He gives it to whom He wills, and they are the believers.
{مآ أصاب من مصيبة فى الا رض ولا فى أنفسكم إلا فى كتاب من قبل أن نبرأهآ إن ذلك على الله يسير * لكيلا تأسوا على ما فاتكم ولا تفرحوا بمآ ءاتاكم والله لا يحب كل مختال فخور * الذين يبخلون ويأمرون الناس بالبخل ومن يتول فإن الله هو الغنى الحميد}
"No disaster strikes upon the earth or among yourselves except that it is in a record before We bring it into being—indeed that, for Allah, is easy. In order that you not despair over what has eluded you and not exult [in pride] over what He has given you. And Allah does not like everyone self-deluded and boastful—[those] who are stingy and enjoin upon [other] people stinginess. And whoever turns away—then indeed, Allah is the Free of need, the Praiseworthy."