From: Maasai, East Africa
Source: Maasai (Kenya, Tanzania) oral-tradition proverb; no. 98 in Joseph Kariuki, "105 Maasai Proverbs Collected From Social Media Forums" (afriprov.tangaza.ac.ke, 2014), which gives the Maa text recorded here and a translation, with no explanation. Jens Finke's "Traditional Music & Cultures of Kenya" (bluegecko.org) is reported to give the same saying as "Olapa oibor inkera"; that page was not re-read for this audit.
The meaning given here is our own reading. Other interpretations exist.