Prescribe that father shall return to the matter being discussed (7)
I believe the answer is:
appoint
'prescribe' is the definition.
(thesaurus)
'father shall return to the matter being discussed' is the wordplay.
I cannot really see how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found within the answer.
'matter' could be 'poi' (poi is a kind of matter) and 'poi' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'that' is the link.
Can you help me to learn more?
(Other definitions for appoint that I've seen before include "Assign job to (someone)" , "Give job to" , "Choose for a job" , "Delegate" , "Pick" .)