en_tn_condensed/luk/20/44.md

David therefore calls the Christ 'Lord,'

In the culture of that time, a father was more respected than a son. David's us of the title 'Lord' for the Christ implies that he was greater than David. (See: rc://en/ta/man/jit/figs-explicit)

so how is he David's son?

"so how can the Christ be David's son?" This can be a statement. Alternate translation: "and this shows that the Christ is not merely David's descendant" (See: rc://en/ta/man/jit/figs-rquestion)