The Hebrew words mean "the well of the exile," and refer to a structure in the time of the Second Temple, mentioned in the Mishnah, that provided water for pilgrims.
Here it has a figurative meaning, alluding to wellsprings of Torah originating in the Jewish diasora.
Born in Vilna, Lithuania. He escaped the Chmielicki massacres of 1648, and settled in Amsterdam.
Concise, but very exhaustive annotations in which the author identifies the source for each ruling in the Shulhan 'Arukh, whether in the Talmud or in medieval rabbinic literature. Only rarely does he add brief explanations of terms.