The particular philologist is of no importance in this case. I've read an article where he deals with a play (and there's a character named Luka there), so his field is literature, not onomastics, I get it. I don't know where he got the information, nor how he comes to give the name such a long meaning 'one born at sunrise' seeing as there's only one element in this name. I'm very interested to know the sources, just like you:)
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Pureness rules the world