en_tn/rev/22/16.md

to testify to you

Here the word "you" is plural. (See: rc://en/ta/man/jit/figs-you)

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. (See: rc://en/ta/man/jit/figs-metaphor and rc://en/ta/man/jit/figs-doublet)

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. See how you translated "morning star" in Revelation 2:28. (See: rc://en/ta/man/jit/figs-metaphor)