The number 18 in the Bible — Life (Chai)
שְׁמוֹנֶה עֶשְׂרֵה
Chai — life, chet + yod — sums to eighteen, which is why Jewish gifts and charity come in multiples of 18 ("giving chai") and why the daily standing prayer is the Shemoneh Esreh, the Eighteen Benedictions. Scripture's own eighteens are mostly oppressions (Judges 3 and 10; Luke 13's deliberate pairing), so the life-meaning comes from the gematria rather than the narratives.
Where 18 shapes the story
Luke 13:11,16 — The daughter of Abraham bound eighteen years — loosed
Judg 3:14 — Eighteen years of oppression, then deliverance
Associations
חי chai = 18 — 'to life!'The Eighteen Benedictions (Amidah)Charity in multiples of chai
Occurrences
Gen 14:14Judg 3:14Judg 10:8Judg 20:25Judg 20:442Sam 8:131Kgs 7:151Kgs 15:12Kgs 3:12Kgs 22:32Kgs 23:232Kgs 24:82Kgs 25:171Chr 12:311Chr 18:121Chr 24:151Chr 25:251Chr 26:91Chr 29:72Chr 11:212Chr 13:12Chr 34:82Chr 35:19Ezra 8:9Ezra 8:18Neh 7:11Jer 32:1Jer 52:21Jer 52:29Ezek 48:35Luke 13:4Luke 13:11Luke 13:16