وَاِذَا
قِیْلَ
لَهُمْ
اٰمِنُوْا
بِمَاۤ
اَنْزَلَ
اللّٰهُ
قَالُوْا
نُؤْمِنُ
بِمَاۤ
اُنْزِلَ
عَلَیْنَا
وَیَكْفُرُوْنَ
بِمَا
وَرَآءَهٗ ۗ
وَهُوَ
الْحَقُّ
مُصَدِّقًا
لِّمَا
مَعَهُمْ ؕ
قُلْ
فَلِمَ
تَقْتُلُوْنَ
اَنْۢبِیَآءَ
اللّٰهِ
مِنْ
قَبْلُ
اِنْ
كُنْتُمْ
مُّؤْمِنِیْنَ
۟
3

The Jews flatly refused to believe in any Book of Allah -- like the Evangel or the Holy Qur'an - except in the Torah. This denial is a clear evidence of their infidelity (Kufr کفر). Moreover, they also used to add that they believe in the Torah, for it had been sent down to them. This comes to mean that they denied the other Books just because they had not been sent down to them. Such an argument betrays their envy and malice.

The Holy Qur'an refutes their argument in three ways:

(1) When the truth and authenticity of the other Books has been established on the basis of irrefutable arguments, what does, then, this denial mean? If they had any doubts as to the arguments on the basis of which authenticity was being claimed for these Books, they could very well have voiced this doubt, and satisfied themselves on this point. But why this flat refusal to believe?

(2) The other Books, like the Holy Qur'an, confirm the Torah..If one denies them, one at the same time denies the Torah itself.

(3) To slay a prophet is tantamount to infidelity (Kufr), according to all the Divine Books. Moreover, the prophets whom the Jews had killed were themselves Israelites, and their teachings, were based on the injunctions of the Torah. But the Jews not only killed these prophets, but also accepted the killers as their chiefs. This is a direct denial of the Torah, and falsifies their claim that they believe in the Torah.

In short, nothing that the Jews say or do is acceptable and valid from any possible point of view.

The next verses proceed to refute the Jews on several other counts.