The literary techniques of synechdoche-metonomy, universal to all languages, states that items can be named by related items, by parts of those items, or by good examples of those items. For example honey refers to anything sweet since honey is a good example of something sweet. Similarly hot refers to matters of love since the two are related. Today's Rashi can best be understood by applying these principles.

The words brother and daughter refer to particular social relationships. However metonomy allows these words to refer to any social relationship, even those not based on family. The following verses, with the referents to brother and daughter enclosed in brackets illustrates this usage.
• Verse Gn29-12a discussing Jacob's relationship to Rachel states And Jacob told Rachel that he was her father’s brother, [actually Jacob was Rachel's father's nephew] and that he was Rebekah’s son; and she ran and told her father.
• Verse Gn31-46a discussing the help Jacob received in making a treaty with Laban states And Jacob said to his brothers, [his children, students and staff] Gather stones; and they took stones, and made a heap; and they ate there upon the heap.
• Similarly verse Gn35=27a discussing the comforting of Jacob while mourning his son's death states And all his sons and daughters [his daughters and daughter-in-laws] arose to comfort Jacob....
As can be seen these verse(s) illustrate a metonomycal use of brother and daughter to refer to any social relationship, even those not based on family.

Advanced Rashi:Rashi on Gn31-46a actually says Brothers: This refers to his children who were brotherly with him in times of danger. However, I, above, translated brothers as meaning [his children, students and staff]. This is an important principle in Rashi - Rashi will often let the obvious comment on a verse be supplied by the reader and will supplement this obvious comment with a non-obvious comment. In this verse it is obvious that to make a heap of stones you call your staff and servants. However family members may not want to indulge in manual labor. Rashi's point is that even the family members helped out also since they wanted to show brotherly solidarity with Jacob in making a treaty. After all, Laban not only mistreated Jacob - he mistreated Jacob's children and their mothers. So yes, Rashi supplements the obvious metonomy - Jacob's servants helped him - with the non-obvious comment that even family members helped.

Similarly the word daughters in Gn35-27a should be understood to refer to both his actual daughters as well as his daughter-in-laws. There is nothing gained by understanding Rashi as interpreting the verse as exclusively referring to his daughter-in-laws; rather we interpret Rashi as indicated that the verse also refers to this daughter-in-laws.

We feel that the understanding of Rashi can be greatly enriched by using this supplemental-method approach to Rashis.