وَمِزَاجُهُۥ مِن تَسْنِيمٍ
Asad Quran Translation
for it is composed of all that is most exalting9
Whereas most of the classical commentators regard the infinitive noun tasnim as the proper name of one of the allegorical "fountains of paradise", or, alternatively, refrain from any definition of it, it seems to me that the derivation of tasnim from the verb sannama - "he raised [something]" or "made [it] lofty" - points, rather, to the effect which the "wine" of divine knowledge will have on those who "drink" of it in paradise. Hence, the tabi'i 'Ikrimah (as quoted by Razi) equates tasnim with tashrif, "that which is ennobling" or "exalting".
Malik Quran Translation
That wine shall have a mixture of Tasnim,
Yusuf Ali Quran Translation
With it will be (given) a mixture of Tasnim: 6026
Tasnim literally indicates height, fulness, opulence. Here it is the name of a heavenly Fountain, whose drink is superior to that of the Purest Wine. It is the nectar drunk by Those Nearest to Allah (n. 5227 to lvi. 11), but a flavour of it will be given to all. See n. 5835 to lxxvi. 5 (Kafur fountain), and n. 5849 to lxxvi. 17-18 (Salsabil).
Mustafa Khattab Quran Translation
And this drink’s flavour will come from Tasnîm—
Piktal Quran Translation
And mixed with water of Tasnim,
Wamizajuhu min tasneemin