The presumption of priestly descent (or presumed kohen or status-quo kohen) in Judaism is the attribution to a kohen of equivalent position as if there was proven descent from the priestly family of Aaron. This is evidenced not by genealogical records but by de facto priestly behavior as defined in rabbinical halakhic texts. In the Land of Israel it was the raising up of hands in the priestly benediction, and sharing heave offering at the threshing floor, whereas in Syria and Babylonia the raising up of hands constituted adequate grounds, but not sharing heave offering at the threshing floor as stated in the Jerusalem Talmud Ketubot 2:7 and other texts. The "presumed kohen" (kohen mukhzaq) (, from חזק) is a rabbinic title which legitimates kohen status to a kohen who—among multiple criteria—exhibits conduct exemplary of and is recognized by his peers and community as such. The tannaitic rabbi Jose ben Halafta extolled the soundness of the said "presumption" (chazakah) by calling it a basis for the entire halakhic concept of chazakah (B.Ketubot 24b). It is based on this presumption that all poskim agree, unanimously, to forbid presumptive kohanim from marrying a divorcee. Of note is that from among the opinions of the Acharonim, the mentioned presumption is given the title "a sound presumption". According to Maimonides, once he is established as a presumptive kohen it is a commandment to sanctify the kohen and assist him in abstaining from the prohibitions that apply to a kohen. Maimonides considered that presumption of the kohen is deemed valid and in good standing unless a valid objection to his lineage is made before a Beit Din. In the Hebrew Bible From the time of Aaron being chosen as High Priest up to the times of the Babylonian exile the lineage of a kohen was taken as matter-of-fact. This changed by the onset of the Jewish nation's returning from Babylonian exile and the building of the temple anew. This national revival created a call for the kohanim to do their necessary priestly duty on the temple. However, due to the occurrence of intermarriage among the returnees in general and the kohanim as well, the need to ascertain that each kohen was lineage verifiable as being a male descendant, 'son after son', also termed 'a paternal grandchild', of Aaron the High Priest and kosher in the literal sense; "in line" with the directives of the Law',