Most people are aware that Hebrew verbs
come from three-letter roots. Each root is
conjugated in the 8 dimensions of
person, gender,plurality, tense, activity,
modality, direct-object, and prepositional connective. For example
the root Shin Mem Resh means to watch.
The conjugations Shin-Mem-Resh-Tauv-Yud
and Nun-Shin-Mem-Resh-Nun-Vav mean
I watched and we were watched respectively.
The rules for Hebrew grammar are carefully described
in many modern books and are well known. Rashi will sometimes comment when a verse is using a rare conjugation
of an odd grammatical form.
When presenting grammatical Rashis my favorite
reference is the appendix in volume 5 of the Ibn Shoshan
dictionary. This very short appendix lists most
Verse Ex19-21 discussing the prohibition of people entering the mountain area during
the decalogue states
And the Lord said to Moses, Go down, charge the people, lest they break through to the Lord to gaze, and many of them perish.
Verse Ex19-24 repeats this prohibition
And the Lord said to him, Go, get you down, and you shall come up, you, and Aaron with you; but let not the priests and the people break through to come up to the Lord, lest he break forth upon them.
As can be seen both verses use the Biblical root Pay-Resh-Tzade, which means to break through.
a possible problem arises in that in one verse the Hebrew word is punctuated with an oh sound -
Yifrotz - while in the other verse it is punctuated with an ah sound - Yifahtz.
The different pronunciations suggests the possibility of different translations. But as seen above both
verses use the same translation!
Rashi explains: A verb conjugated with an oh sound will instead be conjugated with an ah
sound when the verb is in a construct state. Hence we have Yifrotz vs. Yifrahtz-Bam. The change
from oh to ah facilitates the liasoning of the two words.
Advanced Rashi: Notice how this Rashi comment is made on these verses precisely because the conjugated
verb occurs in two different forms clearly suggesting the queestion of which one is right. Very often Rashi
will provide grammatical comments on verses where such contradictory pairs - pairs of words with one small
difference - are present. Such a provision of comments on such verses makes the Rashi comments more natural.