Surah 16. An-Nahl, Ayah 84

An allusion to the Day of Judgment, when the prophets whom God has called forth within every community - or, in the wider sense of the term ummah, within every civilization or cultural period - will symbolically bear witness to the fact that they had delivered God's message to their people and explained to them the meaning of right and wrong, thus depriving them of any subsequent excuse.

According to Zamakhshari, their being "refused permission" to plead is a metonym for their having no valid argument or excuse to proffer. (Cf. also {77:35-36}.)

To each People is sent Allah's Messenger or Teacher, to point out the right way. There may be one, or there may be many. Such a Messenger (Rasul) will be a witness that Allah's Truth was preached to all peoples in express terms, in addition to the Signs of Allah everywhere in nature. There will then be no room for excuses of any kind. Those who rejected Allah after repeated warnings cannot reasonably ask for more respite, as they had every kind of respite during their life of probation; nor can they now take refuge behind Allah's Grace, which they had repeatedly rejected. A) That is, they will not be allowed to seek grace by repentance. Cf. xxx. 57, xlv. 35.