כֹּחַ

From the study of Isaiah 40:29

Range of meaning

Strength, power, ability, capacity to act. It is used of human physical strength (Samson, Judg 16:5), of the produce or yield of land (Gen 4:12, the ground 'will no longer give you its strength'), and very often of God's power in creation and in rescue (Exod 15:6; Jer 10:12).

Against the English

'Power' (KJV, ESV, BSB) and 'strength' (NIV, NASB) both work. Neither English word carries the idea of capacity or yield that kōaḥ can have: the strength something has in order to produce or accomplish.

Used elsewhere in the period

Isa 40:26: God calls out the stars 'because of the abundance of vigour (ʾônîm) and being strong in power (kōaḥ).' Isa 40:31: 'those who hope in the LORD will renew (literally exchange) strength (kōaḥ).' Isa 40:9: 'lift up your voice with strength.'

From the study of Isaiah 40:31

Range of meaning

Strength, power, vigor, capacity. It covers the physical strength of a body (Judg 16:5–6, Samson), the productive power of land (Gen 4:12), and the power of God displayed in creation (Isa 40:26; Jer 10:12).

Against the English

"Strength" is accurate. English versions add "their", which is not in the Hebrew. The Hebrew says simply "they will exchange strength".

Used elsewhere in the period

Isa 40:26 calls God ammits koach, "mighty in strength". Verse 29 uses parallel words for power: onim, "vigor", and otsmah, "might".

From the study of Isaiah 37:3

Range of meaning

Koaḥ: strength, power, physical vigour, capacity (also military might, as in Isa 10:13). Ledah: the act of giving birth (from yalad, 'to bear'). Together: 'the strength needed to bring to birth'.

Against the English

BSB and NIV 'no strength to deliver them' brings in an English pun on 'deliver' (give birth / rescue) that the Hebrew does not have, though it fits the thought. KJV 'not strength to bring forth' is literal. NLT adds 'the mother', which the Hebrew leaves implied.

Used elsewhere in the period

Obstructed labour is a stock image of hopeless crisis in the prophets: Isa 26:17–18 ('we were pregnant, we writhed, we gave birth to wind'); Jer 30:6; Hos 13:13. Claudia Bergmann's study of childbirth as a crisis metaphor treats this verse as a key example.