Qur'an
Surah 2 2:53
وَإِذۡ ءَاتَیۡنَا مُوسَى ٱلۡكِتَـٰبَ وَٱلۡفُرۡقَانَ لَعَلَّكُمۡ تَهۡتَدُونَ ۝٥٣
Remember when We gave Moses the Scripture, and the means to distinguish [right and wrong], so that you might be guided

The Children of Israel worshipped the Calf
Allah then said, "Remember My favor on you when I forgave you for worshipping the calf." This happened after Musa went to the meeting place with his Lord at the end of that period which was forty days. These forty days were mentioned in Surat Al-A`raf, when Allah said,
وَوَعَدْنَا مُوسَى ثَلَـثِينَ لَيْلَةً وَأَتْمَمْنَاهَا بِعَشْرٍ
(And We appointed for Musa thirty nights and added (to the period) ten (more)) (7:142).
It was said that these days were during the month of Dhul-Qa`dah plus the first ten days in Dhul-Hijjah, after the Children of Israel were delivered from Fir`awn and they safely crossed the sea. Allah's statement,
وَإِذْ ءَاتَيْنَا مُوسَى الْكِتَـبَ
(And (remember) when We gave Musa the Scripture) means, the Tawrah,
وَالْفُرْقَانِ
(And the criterion) that is that which differentiates between truth and falsehood, guidance and deviation.
لَعَلَّكُمْ تَهْتَدُونَ
(So that you may be guided aright), after escaping the sea, as another Ayah in Surat Al-A`raf clearly stated,
وَلَقَدْ ءَاتَيْنَا مُوسَى الْكِتَـبَ مِن بَعْدِ مَآ أَهْلَكْنَا الْقُرُونَ الاٍّولَى بَصَآئِرَ لِلنَّاسِ وَهُدًى وَرَحْمَةً لَّعَلَّهُمْ يَتَذَكَّرُونَ
(And indeed We gave Musa ـ after We had destroyed the generations of old ـ the Scripture (the Tawrah) as an enlightenment for mankind, and a guidance and a mercy, that they might remember (or receive admonition)) (28:43).

(And when We gave unto Moses the Scripture), the Torah, (and the Criterion) i.e. We showed in it the lawful and the unlawful, the commands and the prohibitions, as well as other things; it is also said that this means: triumph over Pharaoh, (that you might be led rightfully) guided to avoid error.

EN

And when We gave to Moses the Scripture the Torah and the Criterion wa’l-furqān is an explicative supplement of Torah that is the one that discriminates faraqa between truth and falsehood and between what is licit and illicit so that you might be guided by it away from error.

EN

Torah is the book which was given to Sayyidna Musa (علیہ السلام)
In the language of the Holy Qur'an, al-Furgan الفرقان is a term signifying something which separates truth from falsehood or distinguishes the one from the other. In the present verse, it refers either to (a) the injunctions of the Shari` ah which are to be found in the Torah, for the Shari` ah resolves all the differences that may arise with regard to the doctrines or the practice of good deeds; or to (b) miracles which decide between a true or a false claim in a palpable manner; or even to (c) the Torah itself which has the twin qualities of being a Book of Allah and of being an instrument for separating truth from falsehood.

EN

True piety is to worship God alone, to believe in Him though one has not seen Him, to live in fear of Judgement Day, to subsist on the pure things of the earth, to prevent whomsoever one can from falling into sin. It is those who adopt this way of life who will be successful in the next world.