وَلِكُلِّ أُمَّةٍ رَسُولٌ فَإِذَا جَاءَ رَسُولُهُمْ قُضِيَ بَيْنَهُمْ بِالْقِسْطِ وَهُمْ لَا يُظْلَمُونَ ﴿۴۷﴾ وَيَقُولُونَ مَتَى هَذَا الْوَعْدُ إِنْ كُنْتُمْ صَادِقِينَ ﴿۴۸﴾ قُلْ لَا أَمْلِكُ لِنَفْسِي ضَرًّا وَلَا نَفْعًا إِلَّا مَا شَاءَ اللَّهُ لِكُلِّ أُمَّةٍ أَجَلٌ إِذَا جَاءَ أَجَلُهُمْ فَلَا يَسْتَأْخِرُونَ سَاعَةً وَلَا يَسْتَقْدِمُونَ ﴿۴۹﴾

﴾47﴿ Wa likulli ummatir Rasoolun fa izaa jaaa'a Rasooluhum qudiya bainahum bilqisti wa hum laa yuzlamoon
﴾48﴿ Wa yaqooloona mataa haazal wa'du in kuntum saadiqeen
﴾49﴿ Qul laaa amliku linafsee darranw wa laa naf'an illaa maa shaaa'al laah; likulli ummatin ajalun izaa jaaa'a ajaluhum fa laaa yasta'khiroona saa'atanw wa laa yastaqdimoon

﴾47﴿ And for every nation is a messenger (as a witness over them on the Day of Resurrection). Then when their messenger comes (to testify), it will be judged between them with justice, and they will not be wronged
﴾48﴿ And they say, 'When will this promise be fulfilled if you are truthful
﴾49﴿ Say, "I have no power to harm or benefit myself except as Allah wills. For every nation, there is an appointed time. When their time comes, they cannot delay it by an hour, nor can they hasten it

[47] This verse relates to the fear of the Hereafter. One interpretation of the verse is that for every past nation, there was a messenger. So when that messenger appears on the Day of Judgment and bears witness against his nation, then punishment will befall them—this explanation pertains to the punishment of the Hereafter.
The second interpretation is that for every nation, a messenger was appointed by Allah the Exalted. When that messenger came to them in the world, they denied him—so punishment came upon them in this world. Based on this second interpretation, the verse refers to worldly punishment.
[48] In this verse, there is a warning to the deniers. Since the previous verse alluded to punishment, the disbelievers mockingly asked—out of denial—for the exact time of that punishment: "Tell us when this punishment will occur."
(صَادِقِينَ) – "Truthful ones" is mentioned in the plural form because the address is directed not only to the Prophet (peace be upon him) but also to the believers, implying: "If you (all) are truthful, tell us."
[49] This is the response to the previous statement made by the deniers. The essence of the answer is: “I do not have control over benefit or harm for myself,”—so how could I possibly know the timing of the punishment?
However, it is clear that the punishment does have a fixed appointed time—one that can neither be delayed nor brought forward.
Point of note: A similar verse appears in verse 188 of Surah Al-A‘raf. The only difference is that in that verse, benefit is mentioned before harm, while here, harm is mentioned first. The reason is: in Al-A‘raf, the context was the knowledge of the Day of Judgment—which relates to benefit—so “benefit” was mentioned first. But here, the topic is punishment, which is harm—so “harm” was mentioned first. In both verses, the wording is suited to the context.
Note: This same response has been mentioned in different styles in Surah Al-Mulk (verse 26) and Surah Ya-Sin (verse 49). The reason for the variation is that here, the deniers were challenging the Prophet's messengership—so the response emphasized the status and nature of the Prophet (peace be upon him). But in the other two surahs, the focus was on announcing the punishment—so the reply was tailored accordingly.
(إِذَا جَاءَ أَجَلُهُمْ) – A similar expression is found in verse 26 of Surah An-Nahl and verse 34 of Surah Al-A‘raf.