Genesis 19:37

And the firstborn bare a son, and called his name Moab ,.... As if it was "Meab", from the father, as Aben Ezra, and so Josephus, that is, which she had by her father; and she was so far from being ashamed that it might be known in time to come, she gave him this name. Hillerus F23 Onomastic. Sacr. p. 414. makes it to be a compound of אב and מובא , and to signify "going into", or "lying with a father", which still more notoriously points to her own action. Drusius has another derivation of the word, at least proposes it, and renders it "aqua patris"; "mo" in the Egyptian language signifying "water", which is sometimes used for seed, see Isaiah 48:1 ,

the same is the father of the Moabites unto this day ; a people that lived on the borders of the land of Canaan, often troublesome to the Israelites, and frequently spoken of in the Old Testament.