يَوْمَ لاَ يَنفَعُ الظَّالِمِينَ مَعْذِرَتُهُمْ
...
The Day when their excuses will be of no profit to wrongdoers.
is referring to the same as;
وَيَوْمَ يَقُومُ الاَْشْهَادُ
(...the Day when the witnesses will stand forth).
Others read it with that meaning;
...
وَيَوْمَ يَقُومُ الاَْشْهَادُ
يَوْمَ لاَ يَنفَعُ الظَّالِمِينَ
...
And the Day the witnesses will stand forth, is a Day when there will be no profit to wrongdoers. (and the wrongdoers are the idolators).
مَعْذِرَتُهُمْ
(their excuses),
means, no excuse or ransom will be accepted from them.
...
وَلَهُمُ اللَّعْنَةُ
...
Theirs will be the curse,
means, they will be cast out far away from the mercy of Allah.
...
وَلَهُمْ سُوءُ الدَّارِ
and theirs will be the evil abode.
means, the Hell-fire,
as As-Suddi said, a terrible abode and dwelling place.
Indication that the Messenger and the Believers will prevail just as Musa and the Children of Israel prevailed
Allah says,