en_tn/luk/01/30.md

found favor with God

This could be translated as "God has decided to give you his grace” or “God is being gracious to you" or “God is showing you his kindness.”

will be called the Son of the Most High

This could be translated as "people will call him the Son of the Most High One" or "people will acknowledge that he is the Son of God Most High."

give him the throne of his father, David

give him the throne of his father, David- This could be translated as "give him authority to rule as king like his ancestor David did." The throne represents the king's authority to rule. (See: rc://en/ta/man/translate/figs-metonymy)

his father

The Bible often uses the word "fathers" to refer to ancestors and uses the word "sons" to refer to descendants. The word "his" refers to Mary's son.