Tashlikh

Tashlikh or Tashlich (Hebrew: תשליך "cast off") is a customary Jewish atonement ritual performed during the High Holy Days on Rosh Hashanah.

[2] Rabbi Isaiah Horowitz (born 1555 in Prague — died 1630 in Tiberias) offers the earliest written source explaining the significance of allusions to fish in relation to this custom.

In their view, the custom created the impression among the common people that by literally throwing their sins they might "escape" them without repenting and making amends.

It is generally not practised by Spanish and Portuguese Jews, and it is opposed by the Yemenite Dor Daim movement, and it is not practiced by followers of the Vilna Gaon, mostly in Jerusalem[citation needed].

[11] Congregations have different versions of the traditions depending on factors such as location of the synagogue relative to the closest body of water, as well as the branch of Judaism that the group is in.

That being said, almost all Jewish congregations participate in some version of Tashlich each year and the service has adapted to local characteristics in different communities resulting in various interpretations.