His law I translated into African tongue (7)
I believe the answer is:
swahili
'african tongue' is the definition.
(I've seen this in another clue)
'his law i translated' is the wordplay.
'translated' indicates anagramming the letters.
'his'+'law'+'i'='hislawi'
'hislawi' is an anagram of 'SWAHILI'.
'into' acts as a link.
(Other definitions for swahili that I've seen before include "Language widespread in East Africa" , "Language widely used in East Africa" , "Major Bantu language widely used in E Africa" , "Language of Kenya and lingua franca of other African areas" , "heard in parts of Africa" .)