Quenya 

lo!

(1) interjection "lo!" (VT47:31), also occurring in Aragorn's exclamation when he found the sapling of the White Tree. (Compare yéta-.) Also in the ejaculation yé mána (ma) = "what a blessing" or "what a good thing!" (VT49:41). The more literal meaning would seem to be *"behold the blessing!"