無關痛癢

not to affect sb / irrelevant / of no importance / insignificant

not to have / no / none / not / to lack / un- / -less

unrelated / having nothing to do (with sth else)

mountain pass / to close; to shut; to turn off / to confine; to lock (sb) up; to shut (sb in a room, a bird in a cage etc) / to concern; to involve

ache / pain / sorrow / deeply / thoroughly

pain and itch / sufferings / importance / consequence

to itch / to tickle