The Greek that is translated in English as “beat his breast” or similar is translated in Kasem as “clapped his hands.” To beat one’s breast is considered to be a sign of arrogance and pride. To express regret people clap their hands. (Source: Urs Niggli in Holzhausen / Riderer 2010, p. 16)
Similarly in Bafut (in Luke 23:48): “If we translated the image, ‘beating their breasts’ literally, it would give a wrong meaning. ‘Beating their breasts/chests’ translates in Bafut as ‘ŋ̀kwɛɛ nɨ̂ mɨnt ̀ɨɨ̀ myaa.’ This means they were proud of what they had done. Another consideration is that literally translating ‘beating their breasts’ will mean that it was the women beating their breasts, not men, since, in Bafut, men are perceived as not having breasts. In order to bring out the right meaning using a culturally relevant image, we rendered this as ‘ŋ̀wɛtə mbô myaa,’ and this means ‘crossed their arms’ (under the chin, so the palms rested on the shoulders), which is a sign of mourning in the culture. So in order to explain the symbolic action, the translation added the implicit information, ‘nloŋ mə mɨntɨɨ̀ myaa lɛ nluu nɨ̂ àjəŋnə̀‘ which means, ‘because their hearts were full with sorrow.'” (Source: Michael Suh Niba in Vila-Chã / Hu 2022, p. 233ff.)
In Yaweyuha it is expressed more explicitly as “feeling great sorrow, repeatedly beating their chests” (source: Larson 1998, p. 98) and likewise on Chokwe as “beat his breast for sorrow” (“beat one’s breast” is the equivalent of the English “pat oneself on the back”) (source: D. B. Long in The Bible Translator 1952, p. 87ff.).