the voice

(13:15. And unto Allah falls in prostration whoever is in the heavens and the earth, willingly or unwillingly, and so do their shadows in the mornings and in the afternoons.)

Everything prostrates unto Allah

Allah affirms His might and power, for He has full control over everything, and everything is subservient to Him. Therefore, everything, including the believers, prostrate to Allah willingly, while the disbelievers do so unwillingly,

(and so do their shadows in the mornings), in the beginning of the days,(and in the afternoons.) towards the end of the days. Allah said in another Ayah (Have they not observed things that Allah has created: (how) their shadows incline.)