Rashi would sometimes derive the meaning of a word from the meaning
of its underlying Biblical root. In applying this method Rashi would use all
available grammatical methods to study the
meanings of related roots. The next paragraph presents one such rule.
There are 1900 Biblical roots. Of these 1900 roots about half involve X-Vav-Y X-Y-Y X-Y-Hey pairs. These roots (with one root letter weak) often, but not always, have related meanings. Consequently, very often, but not
always. one can infer the meaning of a X-Y-Y root from the related X-Y-Hey or
Rashi believed in two grammatical systems. He believed in the traditional tri-literial (3-letter) root methods used to conjugate verbs and taught in all elementary schools.
Besides the conjugational root system Rashi also believed in a semantic root system. This is a separate system that enables derivation of root meaning from other roots.
For example the meaning of a 4-letter root, ABCD, is derived from the meaning of its two 2-letter subroots,
Rashi derives the meaning of the 4-letter root, Chet-Resh-Tzade-Nun, Chartzan are follows:
- Cheth-Resh-Tzade-Nun,Chartzan =grape seeds
- Tzade-Nun,Tzinah = thorn
- So Cheth-Resh-Tzade-Nun=Cheth-Resh+ Tzade-Nun that is
- Grape seeds = thorns in a hole