(A recompense in accordance) means: it corresponds to their wicked deeds.
Muhammad said: "Wifaqan" is derived from the word: wafaqa (he agreed with), muwafaqatan (an agreement).
﴿جَزَاء وفَاقا﴾ أَيْ: وَافَقَ أَعْمَالَهُمُ الْخَبِيثَةَ.
قَالَ مُحَمَّد: (وفَاقا) من: وَافقه مُوَافقَة.