I say you are gentle first and last to incite (4)
I believe the answer is:
urge
'to incite' is the definition.
(I've seen this in another clue)
'i say you are gentle first and last' is the wordplay.
'i say you' becomes 'ur' (I can't justify this - if you can you should believe this answer much more).
'first and last' says to hollow out the word (remove centre letters) (only the first and last letters are used).
'gentle' with its middle taken out is 'ge'.
'ur'+'ge'='URGE'
Can you help me to learn more?
(Other definitions for urge that I've seen before include "Appeal to" , "Strong impulse, desire" , "Impel, egg on" , "Strong, restless desire" , "Yen" .)