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)
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.).