Lo and behold!

lo and behold

A phrase used to indicate something surprising or unexpected. I'd been searching for my glasses all over the house when, lo and behold, they were on my head the whole time.
See also: and, behold, lo
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

Lo and behold!

Cliché Look here!; Thus! (An expression of surprise.) Lo and behold! There is Fred! He beat us here by taking a shortcut.
See also: and, lo
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.

ˌlo and beˈhold

(humorous) used when telling a story to introduce somebody’s unexpected appearance: I walked into the restaurant and, lo and behold, there was my boss with his wife.The phrase uses old words that tell you to look at something. It means ‘look and see’.
See also: and, behold, lo
Farlex Partner Idioms Dictionary © Farlex 2017

lo and behold

What a surprise! Can you believe it! The very old word lo, which means “look” or “see,” today survives only in this tautological imperative, which dates from the mid-nineteenth century and is nearly always used lightly. As Edward Bulwer-Lytton wrote (Night and Morning, cited by the OED), “The fair bride was skipping down the middle . . . when lo and behold! the whiskered gentleman advanced.”
See also: and, behold, lo
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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References in periodicals archive ?
Lo and behold! It contained a live insect about two centimetres long and one millimetre thick.
Lo and behold! His phone number was listed in the Houston directory, and when I called, he answered.
Lo and behold! With awful timing that even the Queen couldn't control, two days later Prince Harry's drink and drug habits were splashed all over the papers.
Lo and behold! Out came some 400 elephant calls--a regular concert!
The Story of Mary Surratt (1947), The Curious Savage (1950), and Lo and Behold! (1951) followed in quick succession.