ur'-nest (arrhabon): Found three times in the New Testament: The "earnest of our inheritance" (Eph 1:14); "the earnest of the Spirit" (2Co 1:22; 5:5). It has an equivalent in Hebrew `erabhon (found in Ge 38:17-18,20), in Latin arrabo, French arrhes and the Old English arles. The term is mercantile and comes originally from the Phoenicians. Its general meaning is that of a pledge or token given as the assurance of the fulfillment of a bargain or promise. It also carries with it the idea of forfeit, such as is now common in land deals, only from the obverse side. In other words, the one promising to convey property, wages or blessing binds the promise with an advance gift or pledge partaking of the quality of the benefit to be bestowed. If the agreement be about wages, then a part of the wages is advanced; if it be about land, then a clod given to the purchaser or beneficiary may stand as the pledge of final and complete conveyance of the property.
Figurative: In the spiritual sense, as used in the passages above named, the reference is to the work of the Spirit of God in our hearts being a token and pledge of a perfect redemption and a heavenly inheritance. There is more than the idea of security in the word as used, for it clearly implies the continuity and identity of the blessing.
C. E. Schenk