His law I translated into an African language (7)
I believe the answer is:
swahili
'an african language' is the definition.
(I've seen this before)
'his law i translated' is the wordplay.
'translated' indicates anagramming the letters.
'his'+'law'+'i'='hislawi'
'hislawi' anagrammed gives 'SWAHILI'.
'into' acts as a link.
(Other definitions for swahili that I've seen before include "Major Bantu language widely used in E Africa" , "Language widespread in East Africa" , "Language widely used in East Africa" , "East African language" , "An official language spoken in 15" .)