Robert Christy, comp. Proverbs, Maxims and Phrases of All Ages. 1887.

Supererogation

He has dashed with his oar to hasten the cataract.

He has waved with his fan to give speed to the winds.Terence.

It is needless to pour water on a drowned mouse.

Owls to Athens, coals to Newcastle, enchantments to Egypt, pepper to Hindostan, indulgences to Rome.

To add water to the ocean.Latin.

To carry a lantern in mid-day.French.

To carry water to the sea or river.French, German, Portuguese, Dutch.

You carry faggots to the wood.Horace.

You carry oil to the city of olives.Hebrew.