Muslims,nowadays,have difficulty to admit that Quran confirm Torah authentication,so they interpret that Muhammad didn't confirmed the Torah but only the revelation.
Is that the true understanding of the verse?Lets see how the earlier Muslims understood this verse...
What Tafsir Ibn Katir have to say on this verse:
And when there came to them a Messenger from Allah (i.e. Muhammad ) confirming what was with them), "When Muhammad came to them, they wanted to contradict and dispute with him using the Tawrah. However, the Tawrah and the Qur'an affirmed each other. So the Jews gave up on using the Torah, and took to the Book of Asaf, and the magic of Harut and Marut, which indeed did not conform to the Qur'an. Hence Allah's statement
(http://www.tafsir.com/default.asp?sid=2&tid=2828)
We can learn from this Tafsir what is the simple understanding to Quran readers:
1.When ever Muhammad refer to Torah he refer to the scripts Jews had in his days.
2.The Torah In Muhammad days was authentic.
3.Jews should accepted Muhammad because Torah (and not although Torah...) .
a party of the people of the Book threw away the Book of Allah behind their backs
According Tafsir the book of Allah written in the verse Is the Torah Jews had those days!!!