Our Gemara on Amud Beis uses a verse regarding the Jewish maidservant to derive other forms of enactments that are accomplished via an exchange of an object of value, such as the marriage of a minor through the father’s acceptance:

אָמַר רַב יְהוּדָה אָמַר רַב: דְּאָמַר קְרָא ״וְיָצְאָה חִנָּם אֵין כָּסֶף״ – אֵין כֶּסֶף לְאָדוֹן זֶה, אֲבָל יֵשׁ כֶּסֶף לְאָדוֹן אַחֵר. וּמַאן נִיהוּ – אָב.

Rav Yehuda said that Rav said: The reason is that the verse states with regard to a Hebrew maidservant acquiring freedom from her master: “Then shall she go out for nothing, without money” (Exodus 21:11). The extraneous phrase: Without money, indicates that there is no money for this master, i.e., in this case, the master she leaves loses the money he paid for her, but there is money for a different master, i.e., another master receives money for her when she leaves his authority. And who is the other master who can transfer her to someone else and receives money for her? This is her father.

Numerous commentaries use the entire series of verses in Shemos about servitude and redemption in various metaphorical ways to speak about the soul, the afterlife, its mission in this world, etc. For example, the Jewish slave works for six years, and then it’s free; that is like 69 years of life and then redemption in the world to come (See Alshich and beginning of Mishpatim.) This particular verse is darshened by Be’er Mayyim Chayyim (21:11) in a unique way. The verse states:

וְאִ֨ם־שְׁלׇשׁ־אֵ֔לֶּה לֹ֥א יַעֲשֶׂ֖ה לָ֑הּ וְיָצְאָ֥ה חִנָּ֖ם אֵ֥ין כָּֽסֶף׃

If he does not provide for her these three regular entitlements to a wife at the time that she completes her servitude and he takes as a wife (Food, Clothing, and Intimacy), she shall go free, without payment. (The pashut peshat is saying, even though she was your maidservant, if you marry her, she is to be treated no less than another wife.

The maidservant was only allowed to be sold into service until she reaches marriageable age. After that, the master had to offer to marry her, or marry her off to his son. This was the biblical equivalent of a social welfare program whereby children from impoverished social, economic, and educational backgrounds are given an opportunity to apprentice and eventually join a more advantaged family.

The maidservant who is sold into servitude represents a soul that is enslaved in the trappings of the material world and sin. The three responsibilities according to Be’er Mayyim Chayyim represents the positive and negative commandments, which are like clothing and food for the soul, and intimacy is represented by prayer. Thus, a person who does not live up to those responsibilities toward his soul sends her into spiritual bondage.

The final statement, וְיָצְאָ֥ה חִנָּ֖ם אֵ֥ין כָּֽסֶף׃, refers to the person in the afterlife who was not able to properly feed his soul with Torah and Mitzvot. Now he comes in free of any merit. Yet, as our Gemara says, “Who else receives the money? (Meaning, who compensates for the soul coming in free without any money? The father, that is the Father in Heaven.) Even though the person did not make any merit, somehow, if he still repents, he will be redeemed.