Ifyakulya ubushiku fitulikila ku malushi

Whatever you eat in the darkness of night will be seen in your vomit.

What it means
What you eat under cover of night still shows later, in the open. Secrets and wrongdoing work the same way: what's done in the dark doesn't stay hidden, it just waits until hiding it is impossible.
Bemba · Southern Africa
Source and context
From: Bemba, Southern Africa
Source: Bemba (Zambia) proverb (IFYAKULYA UBUSHIKU FITULIKILA KUMALUSHI); translation and explanation from "Bemba Proverbs And Their Role In Society," The Zambian Observer (zambianobserver.com). Earlier recorded here as also in Laur Mwepu Luiza, "A Collection of 100 Bemba Proverbs" (afriprov.tangaza.ac.ke); that collection was not re-read.

The source explains it: secret deeds cannot remain hidden forever. The wording of the meaning is ours.