They say: "When will this promise (i.e. the Day of Resurrection) come

﴿وَيَقُولُونَ مَتَىٰ هَٰذَا ٱلۡوَعۡدُ إِن كُنتُمۡ صَٰدِقِينَ ﴾
[المُلك: 25]

They say: "When will this promise (i.e. the Day of Resurrection) come to pass? if you are telling the truth

﴿ويقولون متى هذا الوعد إن كنتم صادقين﴾ [المُلك: 25]

Al Bilal Muhammad Et Al
They ask, when will this promise be fulfilled, if you are telling the truth

Ali Bakhtiari Nejad
And they say: when is this promise, if you are truthful

Ali Quli Qarai
They say, ‘When will this promise be fulfilled, if you are truthful?’

Ali Unal
They say (questioning with derision): "When is this promise (of gathering) to be fulfilled, if you are truthful (in your claim)

Hamid S Aziz
And they say, "When shall this promise be (fulfilled) if you are truthful

John Medows Rodwell
And they say, "When shall this threat be put in force, if ye speak the truth

Literal
And they say: "When/at what time (is) that the promise if you were truthful

Mir Anees Original
And they say, “When will this promise (be fulfilled) if you are truthful?”

Mir Aneesuddin
And they say, “When will this promise (be fulfilled) if you are truthful?”