Greek word · G3728

ὁρκωμοσία

horkōmosia

oath

The act of swearing an oath, or a solemn sworn affirmation. It is a compound of horkos (“oath”) and omnymi (“to swear”). It stresses the formal act of taking the oath, not only the oath's content.

Appears 3 times in 3 verses of the Greek New Testament. · Updated October 31, 2026

What it means

ὁρκωμοσία, -ας, ἡ

(ὅρκος, ὄμνυμι; by metapl. for τὰ ὁρκωμόσια, asseverations on oath; see MM, xviii), [in LXX: Ezekiel 17:18 (עָלָה) 1Es 9:93* ;]

affirmation on oath, an oath: Hebrews 7:20-21, 28.†

(AS)

From G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922), via STEPBible.org (CC BY 4.0).

In depth

From the study of Hebrews 7:21

Range of meaning: The act of swearing an oath, or a solemn sworn affirmation. It is a compound of horkos (“oath”) and omnymi (“to swear”). It stresses the formal act of taking the oath, not only the oath's content.
Against the English: English “oath” is accurate. What English loses is how rare and formal the word is. The author picks a weighty technical term and repeats it three times (7:20, 21, 28), so that “oath” works as a structural marker.
Used elsewhere in the period: Rare. BDAG lists it in the Greek Old Testament (Ezekiel 17:18–19, of a broken sworn treaty; 1 Esdras 8:90) and in Josephus (Antiquities 16.163). In the New Testament it appears only in Hebrews 7:20, 21 and 28.

From the study of Hebrews 7:28

Range of meaning: The act of swearing an oath, a solemn oath-taking. A rare, formal compound of horkos ('oath') and omnymi ('to swear').
Against the English: Most versions simply say 'the oath'. KJV and WEB keep 'the word of the oath', which rightly points to a specific spoken text.
Used elsewhere in the period: Rare. It appears in the Septuagint at Ezekiel 17:18–19 (of a king breaking a sworn treaty) and in 1 Esdras. In the New Testament only in Hebrews 7:20, 21 and 28. The oath meant is Psalm 110:4 (LXX 109:4): 'The Lord has sworn and will not change his mind: You are a priest forever according to the order of Melchizedek.' Hebrews 6:13–18 has already argued that God's oath, added to his promise, gives a double guarantee because God cannot lie.

Where it appears

Hebrews · 3

Hebrews 7:20 ὁρκωμοσίας. an oath.

And none of this happened without an oath. For others became priests without an oath,
Hebrews 7:21 ὁρκωμοσίας an oath

but Jesus became a priest with an oath by the One who said to Him: “The Lord has sworn and will not change His mind: ‘You are a priest forever.’”

Here: The formal act of swearing an oath. This is the hinge word of verses 20–28: the oath is what makes this priesthood different from Aaron's.
Hebrews 7:28 ὁρκωμοσίας oath

For the law appoints as high priests men who are weak; but the oath, which came after the law, appointed the Son, who has been made perfect forever.

Here: The act of God swearing an oath. God's oath makes the appointment irrevocable, in contrast to priests installed without an oath (7:20–21).

Word data: STEPBible.org (CC BY 4.0), main text only.