﴿ فَإِذَا فَرَغْتَ فَٱنصَبْ ﴾

“Hence, when thou art freed [from distress], remain steadfast,”

So when thou art relieved) when you finish from military expeditions, jihad and fighting, (still toil) in worship; and it is also said this means: when you finish from the prescribed prayers, make supplications