COMMENTARY on 25:1
Mustafa Khattab:

Translation:
Blessed is the One Who sent down the Standard1 to His servant,1 so that he may be a warner to the whole world.1
Commentary:
1   Al-Furqân, which is one of names of the Quran, means "the standard to distinguish between right and wrong."

 

A. Yusuf Ali:

Translation:
Blessed 3052 is He who sent down the Criterion 3053 to His servant, that it 3054 may be an admonition to all creatures;-
Commentary:

3052  Tabaraka: the root meaning is "increase" or "abundance." Here that aspect of Allah's dealing with His creatures is emphasised, which shows his abundant goodness to all His creatures, in that He sent the Revelation of His Will, not only in the unlimited Book of Nature, but in a definite Book in human language, which gives clear directions and admonitions to all. The English word "blessed" hardly conveys that meaning, but I can find no other without departing far from established usage. To emphasise the meaning I have explained, I have translated "Blessed is . ..", but "Blessed be . .." is also admissible, as it brings out another shade of meaning, that we praise and bless His Holy Name.

3053  That by which we can judge clearly between right and wrong. Here the reference is to the Qur'an, which has already been symbolised by Light This symbol is continued here, and many contrasts are shown, in the midst of which we can distinguish between the true and false by Allah's Light, especially the contrast between righteousness and sin.

3054  The pronoun in yakuna may refer to Furqan (the Criterion) or the 'Abd (the Holy Prophet). In either case the ultimate meaning is the same. The Qur'an is the standing Criterion for judgement between right and wrong.

 

Muhammad Asad:

Translation:
Hallowed is He who from on high, step by step, has bestowed upon His servant the standard by which to discern the true from the false, 1 so that to all the world it might be a warning:
Commentary:
1  Almost all the commentators give this meaning to the term al-furqan. In the above context it denotes the Qur’an as well as the phenomenon of divine revelation as such. (For an amplified interpretation of this term by Muhammad Abduh see note 38 on 2:53.) The verbal form nazzala implies gradualness both in time ("successively") and in method ("step by step").