WaAAala allatheena hadoo harramna kulla thee thufurin wamina albaqari walghanami harramna AAalayhim (surah Anam: 146)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(6:146) And to those who had Judaized We have forbidden all beasts with claws, and the fat of oxen and sheep except the fat which is either on their backs or their entrails, or that which sticks to the bones. Thus did We requite them for their rebellion. *122 Surely We state the Truth.

Wa `alal lazeena haadoo harramnaa kulla zee zufurinw wa minal baqari walghanami harramnaa `alihim shuh oomahumaaa illaa maa hamalat zuhooruhumaaa awil hawaayaaa aw makhtalata bi`azm zaalika jazainaahum bibaghyihim wa innaa lasaa diqoon

*122). This is discussed at three places in the Qur'an. Surah AI 'Imran 3:93 states: 'All food was lawful to the Children of Israel except what Israel made unlawful to themselves before the revelation of the Torah. Tell them: "Bring the Torah and recite any passage of it if you are truthful".' Surah al-Nisa' 4:160 mentions that because of the misdeeds of the Children of Israel: 'We forbade them many clean things which had earlier been made lawful to them.' And now the present verse says that because of the transgression of the Jews, God forbade unto them 'all beasts with claws; and the fat of oxen and the sheep except the fat which is either on their backs or their entrails or that which sticks to the bones'. If these three verses are taken together, it becomes clear that the differences between Islamic law and Jewish law with regard to what is lawful and what is unlawful in animal foods stem from two considerations. First, that several centuries before the revelation of the Torah, Isra'il (Jacob, peace be on him) had given up the use of certain things, which his descendants also abstained from consuming. The result was that Jewish jurists considered them to be absolutely unlawful and recorded their prohibition in the Torah. They included the camel, the hare and the rock-badger, the prohibition of which is mentioned in the fragments of the Torah embodied in the Bible. (See Leviticus ll: 4; Deuteronomy 14: 7) But the Our'an challenges the Jews to come forward with the Torah itself and show where any of those things had been declared unlawful. Their inability to do so shows that those interdictions must have been later interpolations into the Torah.
Second, when the Jews rebelled against the Law revealed by God and set themselves up as their own law-givers, they made several things unlawful for themselves, and as a punishment God allowed them to remain a prey to that misunderstanding. These include birds with claws such as the ostrich, seagull and water-hen, and also the fat of oxen and sheep. In the Bible prohibitions of these kinds have been interpolated among the injunctions of the Torah. (See Leviticus 3:17; 7:22-3; ll:16-18; Deuteronomy 14:14-16.) But Surah al-Nisa' 4:160 shows that those things had not been made unlawful by the Torah itself. They had rather been prohibited after the time of Jesus, and history bears witness to the fact that the present Jewish law was given a definitive formulation by the Jewish jurist, Yehudah, towards the end of the second century of the Christian calendar.
It might be asked in view of what has been mentioned above, why the expression 'We forbade for them' is employed in Surah al-Nisa' 4:160 The answer is that declaration through a Prophet or a heavenly Book is not God's only way of prohibiting. Another way is to allow fraudulent law-makers and sham jurists to gain predominating influence upon God's rebels. These in turn deprive them of many good, clean things of life by making them believe that they are prohibited. The first kind of prohibition is an act of His mercy, whereas the second kind is in the nature of a curse and punishment from God.