Immesurable Things - Mishnah Peah 1:1

(9) When you reap the harvest of your land, you shall not reap all the way to the edges of your field, or gather the gleanings of your harvest. (10) You shall not pick your vineyard bare, or gather the fallen fruit of your vineyard; you shall leave them for the poor and the stranger: I, the Eternal One, am your God.

These are the things that have no measure: The corners [of the field].

First-fruits;

[The offerings brought] on appearing [at the Temple on the three pilgrimage festivals];

Acts of Kindness;

And the study of Torah.

These are the things for which a person enjoys the fruits in this world while the principal reward remains for them in the world to come:

Honoring one’s father and mother;

Acts of kindness;

Bringing peace between a person and their friend;

And the study of Torah is equal to them all.

These are the things that have no measurement: The corners [of the field], The first-fruits, [The offerings brought] on appearing [at the Temple on the three pilgrimage festivals], The performance of righteous deeds, And the study of Torah.

These are precepts, the fruits of which a person enjoys in this world, while the principal reward remains for them in the World-to-Come:

Honoring one's father and mother,

Acts of kindness,

Early attendance in the House of Study morning and evening,

Providing hospitality to guests,

Visiting the sick,

Bringing a bride in [to the chupah], Escorting the dead,

Deep concentration during prayer, Bringing peace between a person and their friend, or between husband and wife — And the study of Torah is equal to them all.

We do not leave peah of less than one-sixtieth [of the field] - even though they said, peah has no measure. Everything depends upon the size of the field, the number of poor people, and the extent of the yield.