It appears that both Jesus and Satan, the devil, are called the Morning Star because Jesus designates the light that came into the world (John 1:4, 7-9; 3:19), and the name of the devil, Lucifer (KJV), means light bearer (Isaiah 14:12, KJV). In Revelation 22:16 it says, “I, Jesus, have sent My angel to testify to you these things for the churches. I am the root and the descendant of David, the bright morning star.”  The second reference is generally regarded to refer to Satan in Isaiah 14:12. Different translations render the Hebrew הֵילֵל [heylel /hay·lale/] differently.  NASB = star of the morning. ESV, RSV = day star.  KJV, NKJV = son of the morning. However, the word is translated into ‘morning star’ in three bibles.

1. Isaiah 14:12, CSB¹Christian Standard Bible, “Shining morning star, how you have fallen from the heavens! You destroyer of nations, you have been cut down to the ground.”
2. Isaiah 14:12, LEB²The Lexham English Bible, “How you have fallen from heaven, morning star, son of dawn! You are cut down to the ground, conqueror of nations!”
3. Isaiah 14:12, NIV84³New International Version (1984), “How you have fallen from heaven, O morning star, son of the dawn! You have been cast down to the earth, you who once laid low the nations!”

However, ‘morning star’ is also used for angels (Job 38:7, NASB, ESV, KJV, RSV, NIV, etc.). So, there seems to be a connection with the phrase in reference to those from heaven since the angels are in heaven, in the presence of God in Jesus, of course, is God in flesh in heaven, and Lucifer used to dwell in heaven.

The phrase seems to find its biblical origin with the concept of a star representing a person, first found in Numbers 24:17, “I see him, but not now; I behold him, but not near; A star shall come forth from Jacob, A scepter shall rise from Israel, and shall crush through the forehead of Moab, And tear down all the sons of Sheth.” The star is a member of Jacob’s family.

The Greek of Revelation 22:16

In Revelvation 22:16, the words ‘morning star’ is πρωϊνός ἀστήρ proēïnós astḗr.

The Hebrew of Isaiah 14:12 and the LXX

In the Hebrew of Isaiah 14:12, the words ‘morning star’ is הֵילֵל [heylel /hay·lale/]. It occurs only once in Hebrew in the entire Old Testament, right here in this verse.

“1966 הֵילֵל [heylel /hay·lale/] n m. From 1984 (in the sense of brightness); TWOT 499a; GK 2122; AV translates as “Lucifer” once. 1 shining one, morning star, Lucifer. 1A of the king of Babylon and Satan (fig.). 2 (TWOT) ‘Helel’ describing the king of Babylon. Additional Information: Lucifer = “light-bearer”.”⁴Strong, James. Enhanced Strong’s Lexicon. Woodside Bible Fellowship, 1995.

In the LXX (The Greek Translation of the Hebrew Old Testament), ‘morning star’ is ἑωσφόρος, eosphoros. (We get the word phosphorous from it).

It is “ἑωσφόρος, ου, ὁ (fr. ἕω, Attic form of Ionic ἠώ ‘dawn, morning’, and φέρω; Hom., Hes.+; LXX, Philo) morning star 2 Pt 1:19 v.l.—DELG s.v. 1 ἕω.”⁵Arndt, William, Frederick W. Danker, Walter Bauer, and F. Wilbur Gingrich. A Greek-English Lexicon of the New Testament and Other Early Christian Literature. Chicago: University of Chicago Press, 2000

Conclusion

In the Hebrew Old Testament “morning Star” is from the Hebrew הֵילֵל [heylel /hay·lale/], which Septuagint translators rendered into the Greek ἑωσφόρος, eosphoros. But, in Revelation 22:16 the Greek word couplet “Morning Star” is two words πρωϊνός ἀστήρ,  proēïnós astḗr. there is a difference between them. But, the similarity is that both deal with light. Therefore, the same phrase “can” be rendered in English as Morning Star.