This is the only way the Ayah can be understood, because this Ummah is better than theirs, as Allah said;
﴿كُنتُمْ خَيْرَ أُمَّةٍ أُخْرِجَتْ لِلنَّاسِ تَأْمُرُونَ بِالْمَعْرُوفِ وَتَنْهَوْنَ عَنِ الْمُنْكَرِ وَتُؤْمِنُونَ بِاللَّهِ وَلَوْ ءَامَنَ أَهْلُ الْكِتَـبِ لَكَانَ خَيْراً لَّهُمْ﴾
(You are the best of people ever raised up for mankind; you enjoin good and forbid evil, and you believe in Allah. And had the People of the Book (Jews and Christians) believed, it would have been better for them) (3:110).
Also, the Musnad and Sunan Collections of Hadith recorded that Mu`awiyah bin Haydah Al-Qushayri said that the Messenger of Allah said,
«أَنْتُمْ تُوَفُّونَ سَبْعِينَ أُمَّةً أَنْتُمْ خَيْرُهَا وَأَكْرَمُهَا عَلَى الله»
(You (Muslims) are the seventieth nation, but you are the best and most honored of them according to Allah.)
There are many Hadiths on this subject, and they will be mentioned when we discuss Allah's statement,
﴿كُنتُمْ خَيْرَ أُمَّةٍ أُخْرِجَتْ لِلنَّاسِ﴾
(You are the best of peoples ever raised up for mankind) (3:110).
﴿وَاتَّقُواْ يَوْمًا لاَّ تَجْزِى نَفْسٌ عَن نَّفْسٍ شَيْئًا وَلاَ يُقْبَلُ مِنْهَا شَفَـعَةٌ وَلاَ يُؤْخَذُ مِنْهَا عَدْلٌ وَلاَ هُمْ يُنصَرُونَ ﴾
(48. And fear a Day (of Judgement) when a person shall not avail another, nor will intercession be accepted from him, nor will compensation be taken from him, nor will they be helped.)
After Allah reminded the Children of Israel of the favors that He has granted them, He warned them about the duration of the torment which He will punish them with on the Day of Resurrection. He said,
(And fear a Day) meaning, the Day of Resurrection,
﴿لاَّ تَجْزِى نَفْسٌ عَن نَّفْسٍ شَيْئًا﴾
(When a person shall not avail another) meaning, on that Day, no person shall be of any help to another. Similarly, Allah said,
﴿وَلاَ تَزِرُ وَازِرَةٌ وِزْرَ أُخْرَى﴾
(And no bearer of burdens shall bear another's burden) (35:18)
﴿لِكُلِّ امْرِىءٍ مِّنْهُمْ يَوْمَئِذٍ شَأْنٌ يُغْنِيهِ ﴾
(Every man that Day will have enough to make him careless of others.) (80:37) and,
﴿يأَيُّهَا النَّاسُ اتَّقُواْ رَبَّكُمْ وَاخْشَوْاْ يَوْماً لاَّ يَجْزِى وَالِدٌ عَن وَلَدِهِ وَلاَ مَوْلُودٌ هُوَ جَازٍ عَن وَالِدِهِ شَيْئاً﴾
(O mankind! Have Taqwa of your Lord (by keeping your duty to Him and avoiding all evil), and fear a Day when no father can avail aught for his son, nor a son avail aught for his father) (31: 33).
This indeed should serve as a great warning that both the father and the son will not be of help to each other on that Day.