Camphor

Root letters:

Kaf-Fa-Ra

kafur

76:5
إِنَّ الأَبْرَارَ يَشْرَبُونَ مِنْ كَأْس ٍ كَانَ مِزَاجُهَا كَافُورا ً
'Inna Al-'Abrāra Yashrabūna Min Ka'sin Kāna Mizājuhā Kāfūrāan 

As for the pious, they will drink from a cup with the scent of musk (camphor).