The word blessing appears 467 times in the Bible. The word bless comes from the Greek word eulogeo which means 'speak well of'. Another word to describe it is 'makarios' which means having the favour of'. We often think of blessing as something that God does but the New Testament has several passages where human beings declare blessings over others.
Bless those who persecute you; bless and do not curse. We labour working with our own hands. Being reviled we bless; being persecuted we endure.
The cup of blessing which we bless, is it not the communion of the blood of Christ? The bread which we break, is it not the communion of the body of Christ? But no man can tame the tongue. It is an unruly evil, full of deadly poison. With it, we bless our God and Father, and with it, we curse men, who have been made the in the similitude of God.