say [OE] Old English secgan is of Germanic origin, related to Dutch zeggen and German sagen. Say, *speak, and *tell are near-synonyms but say is usually followed by the words or statement actually said, giving the verb the sense ‘utter, declare’. When all is said and done dates from the mid 16th century; to say it with flowers was an early 20th century advertising slogan of the Society of American Florists. You can say that again was originally a US usage from the 1940s. The phrase I say, I say, I say to introduce a joke is first recorded from the 1960s.