From Wiktionary, the free dictionary
Literally, “come here grandpa so I can show you your vineyards”.
έλα παππού μου, να σου δείξω τ’ αμπελοχώραφά σου • (éla pappoú mou, na sou deíxo t’ ampelochórafá sou)
- (sarcastic) teach grandma how to suck eggs (telling an expert how to do things)