הלכה אויף משלי 1:8

“Bnei Byshan” had a practice not to travel from Tyre to Sidon on Friday (to avoid detracting from their preparations for Shabbat - Rashi). Their children posed the following question to Rabi Yochanan: “Our fathers were able to abide by this stringent practice because they were wealthy. We, however, find it economically cumbersome to abide by this stringency. Are we obligated to maintain their practice?” Rabi Yochanan answered, “Your ancestors accepted it upon themselves [and you must follow your fathers’ custom], as the pasuk states, “Listen, my son, to the teachings of your father, and do not abandon the Torah of your mother” (Mishlei 1:8).