G2435 — ἱλαστήριον (hilastērion)¶

Core Data¶

Strong's: G2435
Original: ἱλαστήριον
Transliteration: hilastērion
Pronunciation: hil-as-tay-ree-on
Part of Speech: Neuter noun
Root: ἱλάσκομαι (G2433) — to propitiate, expiate
NT Occurrences: 2 (Rom 3:25; Heb 9:5)
First Occurrence: Rom 3:25 — "Whom God hath set forth [to be] a propitiation through faith in his blood..."
Hapax Legomenon: No

Lexicon Definition¶

ἱλαστήριον (hil-as-tay-ree-on); neuter of a derivative of ἱλάσκομαι (G2433); an expiatory (place or thing), i.e., a means of appeasing or expiating. Used in two senses:

The mercy seat — the golden lid of the Ark of the Covenant in the Holy of Holies, sprinkled with expiatory blood on Yom Kippur (Heb 9:5). The LXX uses ἱλαστήριον to render Hebrew כַּפֹּרֶת (kapporeth) throughout Exodus and Leviticus.
An expiatory sacrifice / propitiatory victim — the means of expiation itself; that by which divine righteousness is satisfied and sin is covered (Rom 3:25). (Thayer)

Louw-Nida Semantic Domain¶

Domain: 40 — Reconciliation, Forgiveness
Subdomain: 40.2 — Forgiveness
Other words in subdomain: ἱλάσκομαι (G2433), ἱλασμός (G2434), ἄφεσις (G0859), ἀφίημι (G0863), χαρίζομαι (G5483)

UBS Semantic Domains¶

[040] Reconciliation, Forgiveness — search_relationships.py keeps G2435 in the same reconciliation/forgiveness field as its Louw-Nida placement.

Translation Distribution (KJV)¶

Translation	Count	%
a propitiation	1	50%
mercyseat	1	50%

The two translations represent the same Greek word applied to two different (though theologically connected) referents. English readers using the KJV encounter "propitiation" in Romans and "mercyseat" in Hebrews without realizing it is the identical term.

Distribution by Book¶

Book	Count	Per 100 Verses
Romans	1	0.2
Hebrews	1	0.3

Both occurrences are in the Pauline corpus. The term is rare in the NT precisely because it designates a specific cultic object/role — not a general vocabulary item. Its seven LXX occurrences (Exo 25:17–18; 37:6; 38:7; Lev 16:2 and related) all render H3727 kapporeth.

Semantic Categories¶

1. The Mercy Seat (Physical Tabernacle Object)¶

Heb 9:5 — "And over it the cherubims of glory shadowing the mercyseat; of which we cannot now speak particularly."

The author of Hebrews describes the Tabernacle furniture and identifies the golden lid of the Ark flanked by cherubim as the ἱλαστήριον. This matches the LXX usage throughout Exodus and Leviticus (e.g., Exo 25:22: "I will meet with thee from above the mercy seat").

2. Christ as the Propitiatory¶

Rom 3:25 — "Whom God hath set forth [to be] a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God."

Paul applies ἱλαστήριον to Christ himself. The anarthrous form (no article) highlights function: Christ is the propitiatory — both the place where divine righteousness is publicly displayed and the means by which sin is covered through blood. The typological chain from the OT mercy seat is intentional: what happened annually by priestly blood-sprinkling at the kapporeth now happens once-for-all publicly at the cross.

Common Collocations¶

(With only 2 verses, co-occurrences reflect immediate literary contexts, not statistical patterns.)

Word	Strong's	Context
αἷμα (haima)	G129	Rom 3:25 — "through faith in his blood" — blood as the expiatory instrument
πίστις (pistis)	G4102	Rom 3:25 — "through faith" — the human appropriation of propitiation
δικαιοσύνη (dikaiosyne)	G1343	Rom 3:25 — "his righteousness" — the divine attribute publicly displayed
χερουβίμ (cherubim)	G5502	Heb 9:5 — the cherubim overshadowing the mercy seat in the sanctuary

Word Family (hilask- root)¶

G2433 ἱλάσκομαι (hilaskomai) — verb: to propitiate, expiate, be merciful (2x: Luke 18:13; Heb 2:17)
G2434 ἱλασμός (hilasmos) — noun: propitiation, the atoning act or event (2x: 1 John 2:2; 4:10)
G2436 ἵλεως (hileōs) — adjective: propitious, gracious, merciful (2x: Matt 16:22; Heb 8:12)

Synonyms¶

No direct synonyms were returned by search_relationships.py for G2435. The tool instead surfaced adjacent reconciliation/forgiveness vocabulary in the same semantic field.

Antonyms¶

No antonyms were returned by search_relationships.py for G2435.

Easily Confused Words¶

Word	Strong's	Shared Translation	Key Difference
ἱλασμός (hilasmos)	G2434	both → "propitiation" (KJV)	hilasmos is abstract — the act or event of atonement (1 John 2:2; 4:10); hilastērion is concrete — the place, object, or person that is the propitiatory (Rom 3:25; Heb 9:5)

Hebrew Source¶

Hebrew Source	Strong's	LXX Co-occurrences	PMI Score	Notes
כַּפֹּרֶת (kappôreth)	H3727	16x	9.75	Primary: mercy seat / atonement lid of the Ark
כְּרוּב (kᵉrûwb)	H3742	7x	6.93	Cherub — contextually flanks the mercy seat in the same passages
אָרוֹן (ʼârôwn)	H727	6x	5.31	Ark of the Covenant — appears in the same Exo/Lev passages as kapporeth

The dominant LXX usage is for H3727 kapporeth (the mercy seat/atonement cover). The cherub and ark co-occurrences are architectural context — LXX passages describing the mercy seat invariably describe its setting. The LXX translators chose ἱλαστήριον over a simple transliteration, foregrounding the object's expiatory function rather than its physical description.

Domain Neighbors (Louw-Nida 40.2 — Forgiveness)¶

Strong's	Lemma	NT Occurrences	Primary KJV Translation
G2433	ἱλάσκομαι	2	be merciful, make reconciliation for
G2434	ἱλασμός	2	the propitiation
G859	ἄφεσις	14	forgiveness, the remission
G863	ἀφίημι	36	forgive, left
G5483	χαρίζομαι	5	forgave, forgiving