(only speaking from what I think I understand mercy to be)
‘Chesed’ is the Hebrew word for mercy. “His mercy endures forever” is a constant refrain of the unmerited favor, compassion and forgiveness of God that is extended toward us as expressed in the Psalms so extensively.
‘Chesed’ is from a root word, ‘chawsad’ meaning to bow the head toward someone as considering that person one’s equal.
The NT equivalent word that is translated ‘mercy’ is also very much akin to the word translated as ‘alms’. So one might conclude that merciful acts would include any prayer, gesture, word, kindness, or gift that exhibits compassion, empathy, forgiveness, or charity toward another human being in the attitude of humble equality with that person.
The OT speaks predominantly of the mercy of God.
The NT speaks predominantly of the mercy that we are to give each other and to all. These prayers, words, gestures, gifts and acts of mercy toward others are from the outflowing mercy that we have received from God through our Lord Jesus Christ with
quiet humility and gratitude towards God.
Jesus quotes the prophet, when he says, "learn what is meant by, ‘I desire mercy, and not sacrifice’."
Perhaps Lent is the optimal time to show forth mercy toward one another.
God’s peace be with you