Abarim Publications' online Biblical Hebrew Dictionary
The root-verb יתן (ytn) does not occur in the Bible but in cognate languages it denotes permanence or perpetuity, especially of water.
The only extant Hebrew derivative of this root is the adjective איתן ('etan), meaning perennial, ever-flowing. This word refers to wadies that never run dry, which is of course an important feature in a dry land such as Palestine, but it also serves as a beautiful metaphor for God's never ceasing mercies (Deuteronomy 21:4, Amos 5:24, Psalm 74:15, Micah 6:2). This word occurs 13 times in the Bible.