Rivard

Blessing manifests itself primarily as the power of fertility, both within the family and in the practice of farming, and as such represents a sharing in the life of God and the power to pass on that life by virtue of the blessing of creation.

- Derek A. Rivard, Blessing the World: Ritual and Lay Piety in Medieval Religion. (Washington, D.C: Catholic University Press, 2009), 27.

This definition of blessing comes from the historical-critical viewpoint. From a theological point of view the historical-critical is limited because it doesn't regard the Church as it is, instituted by Christ as the means for salvation of all mankind. Rather it views the Church as a historical accident... (that's strong but that's what this kidn of definition ignores is the spiritual authority of the Church.)

Rivard

The origins of Christian blessing are to be found in the scriptural tradtiions of the ancient Isrealites. THe theology of the Old Testament does not primarily emphasize blessing and God's rolt in it, focusing its attention rather on God as one who saves, a God of deliverance.

-Derek A. Rivard, Blessing the World: Ritual and Lay Piety in Medieval Religion. (Washington, D.C: Catholic University Press, 2009), 25.

Rivard's presentation on blessings represents a contemporary view of blessing which heavily emphasizes the historical understanding of blessings which is heavily dependant upon the scholarship of Westermann, whom Rivard cites here.