Comments in the book on chiropody? (9)

'comments' is the definition.
(footnote is a kind of comment)

'the book on chiropody?' 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.
'book' could be 'ot' (Old Testament) and 'ot' is located in the answer.
'on' is present in the answer.
The remaining letters 'foes' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

'in' acts as a link.

Can you help me to learn more?