Humbly ask if you may hold an opposing view? (3,2,6)
I believe the answer is:
beg to differ
'an opposing view?' is the definition.
The definition suggests a verb in its base form which matches the answer.
'humbly ask if you may hold' is the wordplay.
I cannot really understand how this works, but
'ask' could be 'beg' (begging is a kind of asking) and 'beg' is found in the answer.
'if' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Another definition for beg to differ that I've seen is " Politely disagree".)