en_tn_condensed/rev/22/16.md

to testify to you

Here the word "you" is plural.

the root and the descendant of David

The words "root" and "descendant" mean basically the same thing. Jesus speaks of being a "descendant" as if he were a "root" that grew out of David. Together the words emphasize that Jesus belongs to the family of David.

the bright morning star

Jesus speaks of himself as if he were the bright star that sometimes appears early in the morning and indicates that a new day is about to begin.