tn The construction uses the imperfect tense followed by the infinitive absolute, יָמוּת מֵת (yamut met). Because the verb is in a conditional clause, the emphasis that is to be given through the infinitive must stress the contingency. The point is “if someone dies—unexpectedly.” The next words underscore the suddenness of this.
tn The verb is the Piel perfect with a vav (ו) consecutive; it continues the idea within the conditional clause.
sn The expression is figurative for the vow that he took; the figure is the metonymy because the reference to the head is a reference to the long hair that symbolizes the oath.