There is a coherent theme to each parsha in Chumash, and the parshios
begin and end where they do for logical reasons having to do with the
particular subject matter covered within the parsha. Identifying an
overall theme to a particular parsha is generally more challenging in
Parshas Matos covers three broad subjects: (1) nedarim/vows, (2) the war
against Midyan and dealing with the captured people and property and (3)
the desire of Bnei Reuven and Gad to settle on the east side of the Jordan.
[By the way, thematically it is interesting that the unusual word Matos
appears separately, one time each, in all three subjects: 30:2 31:4, and
On a simple level, perhaps the unifying theme is verbal expression and the
koach hapeh (power of the mouth).
1. Nedarim/vows obviously relates to verbal expression and includes the
famous exhortation of k'chol hayotzey mipiv ya'aseh ('he should do
whatever comes out from his mouth', meaning do what you say you're going
to do). (30:3)
2. While the war against Midyan would not seem to be related to speech,
Rashi points out (31:9) that Klal Yisroel's strength in war derives from
the prayers they utter with their mouths, as distinct from Midyan/Eisav
who uses the sword for strength.
3. The tribes of Reuven and Gad wanted to stay on the east of the Jordan
River. Moshe strongly objected on the grounds that their staying put would
be interpreted by the rest of Klal Yisroel as a lack of confidence in
their ability to conquer the Land. Reuven and Gad then assured Moshe that
that they would send their men to fight the wars of conquering the Land,
and only afterwards would the men return to the east side of the Jordan.
Moshe accepted this, but he warned them explicitly 'v'hayotzeh mipichem
ta'asu' - do what you say you're going to do (32:24). In addition, both
Moshe and Bnei Reuven/Gad refer to the east side of the Jordan where they
then stood as 'poh'/here. 32:6 and 32:16. The word poh/here and peh/mouth
have the same letters in Hebrew. [Perhaps this is because through speech
the peh/mouth gives definitiveness and presence to our intangible and ever
changing thoughts. Once spoken by the peh it becomes poh, meaning it has
arrived here and is now real.]