67:25
وَيَقُولُونَ مَتَىٰ هَـٰذَا ٱلْوَعْدُ إِن كُنتُمْ صَـٰدِقِينَ ٢٥
Saheeh International
And they say, "When is this promise, if you should be truthful?"
Tafsir of "Ibn Kathir" (English)
They say:"When will this promise come to pass if you are telling the truth"meaning, `when will this gathering after separation that you are informing us of, occur