Positive commandment · Mitzvat Aseh #243 of 613
To render judgment [in questions] regarding a paid watchman
לדון בדין נושא שכר ושוכר
The verse · Shemot 22:9
כִּי־יִתֵּן אִישׁ אֶל־רֵעֵהוּ חֲמוֹר אוֹ־שׁוֹר אוֹ־שֶׂה וְכׇל־בְּהֵמָה לִשְׁמֹר וּמֵת אוֹ־נִשְׁבַּר אוֹ־נִשְׁבָּה אֵין רֹאֶה
“If a man deliver to his neighbour an ass, or an ox, or a sheep, or any beast, to keep; and it die, or be hurt, or be driven away, no man seeing it:”
The Rambam’s words
To render judgment [in questions] regarding a paid watchman, as [Exodus 22:9] states: "Should a person give a donkey or an ox...."
לדון בדין נושא שכר ושוכר, שנאמר: "כי ייתן איש אל ריעהו חמור או שור" (שמות כב,ט).
Why · Sefer HaChinuch #59
The commandment on the court to judge the case of one who takes a wage and of a renter
“The root of the laws is well-known.”
Who & when
“And [it] is practiced by males in every place and at all times.”
Where in the Mishneh Torah
Hilchot Hiring הלכות שכירות