So what beings periodically give people a hand? (3,4)
I believe the answer is:
big deal
'so what' is the definition.
(both can express a lack of interest)
'beings periodically give people a hand?' is the wordplay.
'periodically' indicates alternate letters (letters must be selected 'every so often').
'give people a hand?' becomes 'deal' (to deal a 'hand' in card games).
The alternating letters of 'beings' are 'big'.
'big'+'deal'='BIG DEAL'
(Other definitions for big deal that I've seen before include "Exclamation of scorn, belittling a claim" , "sarcastic response" , "doesn't impress me at all" , "Successful piece of business (ironical)" , "In slang, I'm not impressed - by large wood?" .)