[Saying:] "O descendants of those whom We carried with Noah," meaning: O descendants; therefore it is in the accusative case (mansub).
﴿ذُرِّيَّةَ مَنْ حَمَلْنَا مَعَ نُوحٍ﴾ أَيْ: يَا ذُرِيَّةَ؛ لِذَلِكَ انْتَصَبَ.