The headword -- present indicative active, third person singular, of proskune/w (see also pi 2747) -- is normally construed with a dative object. The quotation given demonstrates the syntactical assertion that it can also be construed with an accusative object.
[1] Quotation not identified by Adler but identifiable via the TLG as coming from a troparion (hymn) for the Feast of the Nativity; it alludes to Malachi 3:20 LXX, where the phrase 'sun of righteousness' appears.