From: Chewa, Southern Africa
Source: Chewa (Malawi, Zambia) proverb (Chaona mnzako chapita mawa chili paiwe); translation and explanation from "Chichewa Proverbs (Zambia, Malawi, Mozambique, Zimbabwe): 18 in Total," African Manners (africanmanners.wordpress.com), 2012. "Chewa Proverbs And Their Role In Society," The Zambian Observer (zambianobserver.com), gives a variant of the saying with the lesson "never laugh at a neighbors' misfortunes because these same misfortunes may one day fall on you". Earlier recorded here as documented in Toon van Kessel's "Collection of 1000 Chewa Proverbs" (FENZA, 2015); that book was not read.
The source explains it: The moral message is that it is right to help those who are in need of our help
. The wording of the meaning is ours.