﴿ وَٱلسَّمَآءِ ذَاتِ ٱلرَّجْعِ ﴾

“Consider the heavens, ever-revolving,”

وَالسَّمَاءِ ذَاتِ الرَّجْعِ (I swear by the sky that rains...86:11) The word raj refers to 'the rain that comes down repeatedly'. In other words, the rain that comes down and stops and then returns.