Yigdalyahu (יִגְדַּלְיָהוּ) is a theophoric name meaning "Yahweh is great\” or "May Yahweh be magnified\”, from the root gadal (to be great, to magnify). The name appears once in Jeremiah 35:4, identifying a man of God whose sons kept a chamber in the Temple.
The root gadal carries the full weight of divine magnification — the same root appears in Psalm 34:3 ("O magnify the LORD with me") and Mary's Magnificat (Luke 1:46, translating megalynō). To bear the name "Yahweh is great" was to carry a doxological proclamation in one's very identity.
The brief mention of Yigdalyahu in Jeremiah 35 places him in the era of the Rechabites — a context of covenant faithfulness contrasted against Judah's apostasy. His sons kept a room in the Temple of the LORD, suggesting a household committed to sacred service. Even peripheral figures in Scripture often carry names that preach: Yahweh is great, even when His people are faithless.