The special word method deals with the
few dozen special words that exist in all languages.
Familiar examples are also, when, that, because, only,
this,.... Rashi's job, when he comments on a special connective
words, is to list the varied nuances and usages of the word.
The most famous example is the Hebrew word Kaph Yud
which can mean because, that, when, perhaps, rather, if.
Sometimes Rashi explicitly gives all meanings of a connective
word as happens with Kaph Yud while at other times
Rashi does not give all meanings at once. In such a case the
student must gather all the meanings together from various
Rashi following the Talmudic exegetes re-interpreted all
superfluous relative pronouns as being modified with the
adverb, only. This gives an unspecified restrictive
emphasis. Hence Rashi interprets verse Ex13-09c by inserting
the underlined word only:
Speak ye unto all the congregation of Israel, saying: In the tenth day of only this month they shall take to them every man a lamb, according to their fathers' houses, a lamb for a household;
The actual Rashi comment is: Only the original Passover
in Egypt required separating the Pascal meal offering on the
10th of Nissan.