The context refers to that Day which represents a fundamental case in human’s life. This Day is recognized in two matters; the first, a soul will not possess for another soul a power to do a thing, the second, the command that Day is entirely with Allah.
In this worldly life, a soul can possess a power over another soul but on the Last Day there is no place for these reasons, the souls in this life are connected to reasons and humans may help each other, while on the last Day none of that will be, and no one possesses any harm or good to do to anyone else.
You may ask: In this life is not the command is entirely with Allah (swt)? The answer is: Yes, it is entirely with Allah (swt), but there are reasons connected to causers, while on that Day you are with the Causer without reasons, so the command is entirely with Allah (swt).