tell it/that to the marines
(go) tell it/that to the marines
A scornful or incredulous response to a story or statement that one does not believe or finds ridiculous. A: "You know, my dad used to play basketball with the president when they were both kids." B: "Ah, go tell it to the marines! Why do you tell such fibs?" A: "I bet you I could eat 20 hot dogs in less than half an hour!" B: "Tell that to the marines, pal!"
tell it to the Marines
Go fool someone else because I won't believe that. For example, He's a millionaire? Tell it to the Marines! This term originated among British sailors, who regarded marines as naive and gullible. [c. 1800]
tell that to the marines (or the horse marines)a scornful expression of incredulity.
This saying may have originated in a remark made by Charles II , recommending that unlikely tales should be referred to sailors who, from their knowledge of distant places, might be the people best qualified to judge their truthfulness. Horse marines, dating from the early 19th century, were an imaginary cavalry corps, soldiers mounted on horseback on board ship being a humorous image of ineptitude or of people out of their natural element. In 1823 Byron noted that That will do for the marines, but the sailors won't believe it was an ‘old saying’, and the following year Walter Scott used Tell that to the marines—the sailors won't believe it! in his novel Redgauntlet.
1998 Times Truth is the issue, say the apologists, not the grope. You can tell that to the marines. The issue is the grope.
(go) tell it/that to the maˈrines(saying, informal) used to say that you do not believe what somebody is saying, promising, etc: ‘I’ll never smoke again!’ ‘Yeah? Go tell that to the marines.’This comes from the saying ‘that will do for the marines but the sailors won’t believe it’.
Tell it to the marines
A scornful response to an unbelievable story. Beginning in the 17th century, marines were land forces who were stationed on ships of the Royal Navy. As landlubbers, they were understandably naive if not ignorant about life aboard a vessel and on the waves. Sailors took advantage and concocted outlandish stories that the marines swallowed hook, line, and sinker. Accordingly, any outlandish story heard on land or sea and recognized as bilge was greeted with the full rejoinder, “You may tell that to the marines, but the sailors will not believe it,” subsequently shortened over generations to “Aw, tell it to the marines!”