en_tn_lite_do_not_use/luk/20/41.md

How do they say

This is a rhetorical question. It can be translated as "Why do they say" or "Let's think about them saying" or "I will talk about them saying." (See: rc://en/ta/man/translate/figs-rquestion)

David's son

"King David's descendant." The word "son" is used here to refer to a descendant. In this case it refers to the one who would reign over God's kingdom. (See: rc://en/ta/man/translate/figs-synecdoche)

The Lord said to my Lord

This can be translated as "The Lord God said to my Lord" or "God said to my Lord." This is a quotation from Psalm Psalms 110:1 which says "Yahweh said to my Lord." But the Jews stopped saying "Yahweh" and often said "Lord" instead.

my Lord

David was referring to the Christ as "my Lord."

my right hand

The right side is the place of honor. God was honoring the Messiah by saying "Sit at my right hand."

until I make your enemies your footstool

This is a metaphor. It can be translated as "until I make your enemies like a footstool for you" or "until I conquer your enemies for you." (See: rc://en/ta/man/translate/figs-metaphor)

so how is he David's son?

"so how can the Christ be David's son?" This is a rhetorical question. It can be translated as "This shows that the Christ is not merely David's descendant." (See: rc://en/ta/man/translate/figs-rquestion)