beat a dead horse

listen to the pronunciation of beat a dead horse
İngilizce - Türkçe
(deyim) Boşa kürek çekmek, boşa çabalamak
İngilizce - İngilizce
To persist or continue far beyond any purpose, interest or reason

After having shown us three hours of instructional and safety videos, the inspector was simply beating a dead horse by telling us to buckle up as we got into the van.

(deyim) Waste time on something that is a lost cause or likely to be unproductive, flog a dead horse [Brit]
(Slang) continue to deal with an issue after it has been settled; waste time on a task that will never succeed
beat a dead horse