Surah Al Isra Tafseer

وَجَعَلْنَا عَلَى قُلُوبِهِمْ أَكِنَّةً

And We have put coverings over their hearts,

Akinnah (coverings) is the plural of Kinan, which covers the heart.

أَن يَفْقَهُوهُ

lest they should understand it,

means, lest they should understand the Qur'an.

وَفِي اذَانِهِمْ وَقْرًا

and in their ears deafness,

something that will stop them from hearing the Qur'an in such a way that they will understand it and be guided by it.

وَإِذَا ذَكَرْتَ رَبَّكَ فِي الْقُرْانِ وَحْدَهُ

And when you make mention of your Lord Alone in the Qur'an,

means, when you declare Allah to be One in your recitation, and say La Ilaha Illallah,

وَلَّوْاْ

they turn,

means they turn away ,

عَلَى أَدْبَارِهِمْ نُفُورًا

on their backs, fleeing in extreme dislike.

As Allah says:

وَإِذَا ذُكِرَ اللَّهُ وَحْدَهُ اشْمَأَزَّتْ قُلُوبُ الَّذِينَ لَا يُوْمِنُونَ بِالاٌّخِرَةِ

And when Allah Alone is mentioned, the hearts of those who believe not in the Hereafter are filled with disgust (from the Oneness of Allah).(39:45)

وَإِذَا ذَكَرْتَ رَبَّكَ فِي الْقُرْانِ وَحْدَهُ

And when you make mention of your Lord Alone in the Qur'an,

Commenting on this Ayah, Qatadah said that;

when the Muslims said La Ilaha Illallah, the idolators disliked this and found it intolerable.

Iblis and his troops hated it, but Allah insisted on supporting it so that it would prevail over those who opposed it. Whoever uses it against his opponent will prevail, and whoever fights for it will be victorious. Only the Muslims of the Arabian Peninsula, which can be traversed by a rider in a few nights, knew it and accepted it, out of all mankind