فَمَهِّلِ الْكَافِرِينَ أَمْهِلْهُمْ رُوَيْدًا
Grant the disbelievers respite; grant them a little respite.
The second clause reinforces and specifies the first command. They express one tightly integrated meaning: complete connection.
إِنَّمَا نَحْنُ مُسْتَهْزِئُونَ اللَّهُ يَسْتَهْزِئُ بِهِمْ
“We were only mocking.” Allah requites their mockery.
The second is not a repetition of the first. Their meanings relate, but the first is the hypocrites’ speech and the second a divine statement, so they cannot share the same scope: the intermediate case.