The Koine Greek particles ἰδού and ἴδε have been traditionally translated as either 'behold' or 'lo'. But such mechanical renderings are inadequate as they suggest these particles can be reduced to a single meaning or function. As argued in this monograph, these particles actually have several distinct uses that are conditioned by their linguistic context, and a translator should find natural idioms in the receptor language that match the meaning and function of these Greek uses.