Marrying outside the faith and betraying the sacred covenant carries a heavy price: the complete physical and spiritual severing of the sinner’s legacy from the nation of Israel. God will entirely erase the family line of anyone who commits this act of betrayal, leaving no trace behind, regardless of whether the offender is an ordinary person, a scholar, or a priest [מצודת דוד, ביאור שטיינזלץ].
The nature of this erasure is understood in two primary ways. The first is a literal, physical end to the family line. In this view, the punishment decrees that no living person will remain in the sinner's household. Just as the dead are compared to those who sleep, the curse ensures there will be no one left awake to answer a knock at the family's door [רד״ק, אברבנאל, מלבי״ם]. Alternatively, this total cutoff means that both the young and the old, or the son and the grandson, will be wiped out, bringing the family dynasty to a definitive close [אבן עזרא, רד״ק, אברבנאל, ביאור שטיינזלץ].
On the other hand, a spiritual approach focuses on the loss of legacy within the halls of study. According to this view, the sinner is doomed to never have descendants who study God's laws. The imagery of being alert and responsive is applied to intellectual sharpness. The sinner will have no sharp-minded student capable of challenging a teacher with questions, nor a fully alert scholar able to resolve complex doubts. They will not even have a drowsing student who can provide an answer when roused [רש״י, מצודת דוד, מלבי״ם, רד״ק, אברבנאל].
The consequences extend specifically to the spiritual leadership as well. For a priest who commits this abomination, the punishment strikes directly at his sacred duties. He will leave behind no son to inherit his role and bring offerings before God. This severe warning is directed at the priesthood because, during that historical period, even the priests failed by marrying foreign women [רד״ק, אברבנאל]. Ultimately, the children of these priests will follow the ways of their foreign mothers, losing their rightful place in both the service of the Temple and the study of the law [מלבי״ם].