1,920. Rabbinic Betrothals and Yibum

Yibum v’Chalitzah 5:22

The same rules regarding a minor yavam of nine years and a day also apply to a yavam of 20 years of age who hasn’t exhibited the signs of physical maturity but who also hasn’t exhibited the signs of congenital infertility, as was discussed in Hilchos Ishus.

Yibum v’Chalitzah 5:23

Also as discussed in Hilchos Ishus, the betrothal of a minor girl who can unilaterally dissolve her marriage through refusal and the betrothal of a woman with congenital deafness are rabbinic enactments, albeit of two different natures. The betrothal of a minor was enacted to prevent men from treating her frivolously; therefore, her betrothal is tentative until she reaches the age of majority. Betrothal for a woman with congenital deafness was enacted so that she would not have to remain perpetually single. Accordingly, if all the yevamos from the same household are minors or have congenital deafness, engaging in relations with one of them absolves all of them of their levirate obligation.