One must be patient with it for a long time (6,7)

'time' is the definition.
Both the answer and definition are singular nouns.
Maybe you can see a link between them that I can't see?

'one must be patient with it for a long' is the wordplay.
I cannot quite understand how this works, but
'one' could be 'i' (Roman numeral) and 'i' is present in the answer.
'it' could be 'e' ('e' can mean 'electronic' which is similar to 'IT') and 'e' is located in the answer.
'long' could be 'l' and 'l' is found in the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?