E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Priests used to wear their ring on the fore-finger (which represents the Holy Ghost) in token of their spiritual office. (See WEDDING FINGER.)
The ring finger represents the humanity of Christ, and is used in matrimony, which has only to do with humanity. (See FINGER BENEDICTION.)
Ring finger. Aulus Gellius tells us that Appianus asserts in his Egyptian books that a very delicate nerve runs from the fourth finger of the left hand to the heart, on which account this finger is used for the marriage ring. (Noctes, x. 10.)
The fact has nothing to do with the question; that the ancients believed it is all we require to know. In the Roman Catholic Church, the thumb and first two fingers represent the Trinity: thus the bridegroom says, In the name of the Father, and touches the thumb; in the name of the Son, and touches the first finger; and in the name of the Holy Ghost he touches the long or second finger. The next finger is the husbands, to whom the woman owes allegiance next to God. The left hand is chosen to show that the woman is to be subject to the man. In the Hereford, York, and Salisbury missals, the ring is directed to be put first on the thumb, then on the first finger, then on the long finger, and lastly on the ring-finger, quia in illo digito est qudam vena procedens usque ad cor.
The ring finger. Mr. Henry Swinburne, in his Treatise of Spousals, printed 1680 (p. 208), says: The finger on which this ring [the wedding-ring] is to be worn is the fourth finger of the left hand, next unto the little finger; because by the received opinion of the learned in ripping up and anatomising mens bodies, there is a vein of blood, called vena amoris, which passeth from that finger to the heart.