Tafsir of Al-Insan 76:21

عاليهم ثياب سندس خضر وإستبرق

Their garments will be of fine green silk, and Istabraq. meaning, among the garments of the people of Paradise is silk and Sundus, which is a high quality silk. These garments will be shirts and similar clothing from the undergarments. Concerning Istabraq (velvet), from it there is that which has a glitter and shimmer to it, and it is that which is worn as outer clothes, just as is well-known in clothing.

وحلوا أساور من فضة

They will be adorned with bracelets of silver, This is a description of the righteous. In reference to those who will be near to Allah, then their description is as Allah says,

يحلون فيها من أساور من ذهب ولولوا ولباسهم فيها حرير

Wherein they will be adorned with bracelets of gold and pearls and their garments therein will be of silk. (22:23) After Allah mentions the outward beautification with silk and ornaments, He then says,

وسقاهم ربهم شرابا طهورا

and their Lord will give them a purifying drink. meaning, it will purify their insides of envy, despise, hatred, harm and the other reprehensible character traits. This is just as we have recorded from the Commander of the believers, `Ali bin Abi Talib, that he said, "When the people of Paradise come to the Gate of Paradise, they will find two springs there. Then it will be as if they were inspired with what to do, so they will drink from one of them and Allah will remove whatever harmfulness there may be within them. Then they will bathe in the other spring and a glow of delight will run all over them. Thus, Allah informs of their outward condition and their inner beauty.'' Allah then says,

إن هذا كان لكم جزاء وكان سعيكم مشكورا