Loving kindness 慈心 / 慈無量

Loving kindness (Skt. maitrī; Pali metta; Tib. བྱམས་པ་, jampa; Wyl. byams pa) — the wish that beings may have happiness and its causes. One of the four immeasurables.

Benefits

The King of Samādhi Sūtra says:

Even an offering throughout billions of realms,

Consisting of gifts infinite in number and variety,

Presented to great beings every day for all eternity,

Could not match the wonder of a mind of love.

Nagarjuna's Precious Garland (2:83–85) speaks of 'eight rewards of love':

Offerings of three hundred pots of food

Made three times each and every day,

Could not match even a portion of the merit

Gained from just a single moment’s loving kindness.

Even if it does not bring you liberation,

It will produce the eight rewards of love:

Gods and humans will care for you,

And they will offer you protection,

You will be happy and know many joys,

No poison or weapon will do you harm,

Effortlessly, you will achieve your aims,

And you will be born in Brahmā’s realm.