وَلَوْ أَنَّهُمْ أَقَامُواْ التَّوْرَاةَ وَالاِنجِيلَ وَمَا أُنزِلَ إِلَيهِم مِّن رَّبِّهِمْ
And if only they had acted according to the Tawrah, the Injil, and what has (now) been sent down to them from their Lord,
meaning, the Qur'an, as Ibn Abbas and others said.
لاأكَلُواْ مِن فَوْقِهِمْ وَمِن تَحْتِ أَرْجُلِهِم
they would surely have gotten provision from above them and from underneath their feet.
Had they adhered to the Books that they have with them which they inherited from the Prophets, without altering or changing these Books, these would have directed them to follow the truth and implement the revelation that Allah sent Muhammad with. These Books testify to the Prophet's truth and command that he must be followed.
Allah's statement,
لاأكَلُواْ مِن فَوْقِهِمْ وَمِن تَحْتِ أَرْجُلِهِم
(they would surely have gotten provision from above them and from underneath their feet),
refers to the tremendous provision that would have descended to them from the sky and grown for them on the earth. Allah said in another Ayah,
وَلَوْ أَنَّ أَهْلَ الْقُرَى ءَامَنُواْ وَاتَّقَوْاْ لَفَتَحْنَا عَلَيْهِم بَرَكَـتٍ مِّنَ السَّمَأءِ وَالاٌّرْضِ
And if the people of the towns had believed and had Taqwa, certainly, We should have opened for them blessings from the heaven and the earth. (7;96)
Allah's statement,
مِّنْهُمْ أُمَّةٌ مُّقْتَصِدَةٌ وَكَثِيرٌ مِّنْهُمْ سَاء مَا يَعْمَلُونَ
And among them is a Muqtasid Ummah, but for most of them; evil is their work.
is similar to Allah's statement,
وَمِن قَوْمِ مُوسَى أُمَّةٌ يَهْدُونَ بِالْحَقِّ وَبِهِ يَعْدِلُونَ
And of the people of Musa there is a community who lead (the men) with truth and establish justice therewith. (7;159)
and His statement about the followers of `Isa, peace be upon him,
فَـَاتَيْنَا الَّذِينَ ءَامَنُواْ مِنْهُمْ أَجْرَهُمْ
So We gave those among them who believed, their (due) reward. (57;67)
Therefore, Allah gave them the highest grade of Iqtisad, which is the middle course, given to this Ummah. Above them there is the grade of Sabiqun, as Allah described in His statement;
ثُمَّ أَوْرَثْنَا الْكِتَـبَ الَّذِينَ اصْطَفَيْنَا مِنْ عِبَادِنَا فَمِنْهُمْ ظَـلِمٌ لِّنَفْسِهِ وَمِنْهُمْ مُّقْتَصِدٌ وَمِنْهُمْ سَابِقٌ بِالْخَيْرَتِ بِإِذُنِ اللَّهِ ذَلِكَ هُوَ الْفَضْلُ الْكَبِيرُ
جَنَّـتُ عَدْنٍ يَدْخُلُونَهَا يُحَلَّوْنَ فِيهَا مِنْ أَسَاوِرَ مِن ذَهَبٍ وَلُوْلُواً وَلِبَاسُهُمْ فِيهَا حَرِيرٌ
Then We gave the Book as inheritance to such of Our servants whom We chose. Then of them are some who wrong themselves, and of them are some who follow a middle course, and of them are some who, by Allah's permission, are Sabiq (foremost) in good deeds. That itself is indeed a great grace. `Adn (Eden) Paradise (everlasting Gardens) will they enter, therein will they be adorned with bracelets of gold and pearls, and their garments there will be of silk. (35;32-33