Bava Batra

in order that an animal may not jump [over the wall]. Let, then, the big trench be made  and not [also] the small one? — Since it is wide, [the animal] might stand in it and jump. Then let the smaller trench be made and not the bigger one? Since it is small, [the animal] might stand on the [outer] edge and jump. How much [space must there be] between the bigger, and the smaller trench? — One handbreadth. MISHNAH. SOME [RELATIVES] INHERIT [FROM], AND TRANSMIT [TO EACH OTHER];  SOME INHERIT  BUT DO NOT TRANSMIT;  [SOME] TRANSMIT RUT DO NOT INHERIT, [AND SOME] NEITHER INHERIT NOR TRANSMIT. THE FOLLOWING INHERIT [FROM], AND TRANSMIT [TO EACH OTHER]: A FATHER [INHERITS FROM,  AND TRANSMITS TO HIS] SONS, AND SONS [INHERIT FROM, AND TRANSMIT TO THEIR] FATHER; AND BROTHERS FROM THE [SAME] FATHER  INHERIT [FROM], AND TRANSMIT [TO EACH OTHER].  A MAN [INHERITS FROM] HIS MOTHER AND [FROM] HIS WIFE [BUT DOES NOT TRANSMIT HIS ESTATE TO THEM  IF HE DIES FIRST]; AND SISTERS' SONS INHERIT [FROM THEIR UNCLES] BUT DO NOT TRANSMIT [THEIR ESTATES TO THEM].  A WOMAN [TRANSMITS HER ESTATE TO] HER SONS AND A WIFE [TO] HER HUSBAND [BUT THEY DO NOT INHERIT FROM THEM]; AND MOTHER'S BROTHERS TRANSMIT [THEIR ESTATES TO THEIR NEPHEWS] BUT DO NOT INHERIT [FROM] THEM. AND BROTHERS FROM THE [SAME] MOTHER NEITHER INHERIT [FROM], NOR TRANSMIT [TO EACH OTHER]. GEMARA. Why does the Mishnah teach first, THE FATHER [INHERITS FROM, AND TRANSMITS TO HIS] SONS, let it first teach, THE SONS [INHERIT FROM, AND TRANSMIT TO THEIR] FATHER, for, in the first place,  one should not commence with [something suggestive of] misfortune