Isac (Isaac) ben Judah, Bickert is mentioned 16 times between 1652 and 1683. His designation in the Stühlingen family tree is 'B1.2.1.1.1'. His father was Judah (Leheman) ben Naphtali, Bickert.
Traces of Isac ben Judah can be found occasionally between 1634 and 1680. He does not appear on a letter of protection, suggesting either that he never married and set up his own household, or that he resided elsewhere. From 1665 on he appears to have resided in Lengnau [R4085; 01.12.1666]. .