Surah Ad Dukhan Tafseer

يَوْمَ لَا يُغْنِي مَوْلًى عَن مَّوْلًى شَيْيًا

The Day when a near relative cannot avail a near relative in aught,

means, no relative will be able to help another relative.

This is like the Ayah:

فَإِذَا نُفِخَ فِى الصُّورِ فَلَ أَنسَـبَ بَيْنَهُمْ يَوْمَيِذٍ وَلَا يَتَسَأءَلُونَ

Then, when the Trumpet is blown, there will be no kinship among them that Day, nor will they ask of one another. (23:101)

وَلَا يَسْـَلُ حَمِيمٌ حَمِيماً يُبَصَّرُونَهُمْ

And no friend will ask a friend (about his condition). Though they shall be made to see one another, (70:10-11)

which means, he will not ask his brother about how he is, even though he can see him with his own eyes.

وَلَا هُمْ يُنصَرُونَ

and no help can they receive,

means, no relative will help another, and no help will come to him from outside