You stand upright this day, all of you, before the
L-rd your G-d: your heads, your tribes, your elders, and your officers,
and all the men of Israel; your little ones, your wives, and your stranger
that is in your camp, from the hewer of your
wood to the drawer of your water (Deuteronomy 29:9-10)
Our sages have said: "All Israel are guarantors for each other"
(Talmud, Shevuot 39a). But a person cannot serve as a guarantor unless he is
more resourceful in some way than the one he is guaranteeing. For example, a
poor man obviously would not be accepted as a guarantor for a rich man's loan.
So if the Talmud says that all
Jews serve as guarantors to each other,
this means that in every Jew there is a quality in which he or she is superior
to all others.
(The Lubavitcher Rebbe)