From: Somali, East Africa
Source: Somali oral-tradition proverb (Af daboolan waa dahab), documented in Somali proverb collections (e.g. Lingalot); its English equivalent, "Speech is silver, silence is gold.", is given in Ismaaciil Madoobe's "Somali Proverbs with Equivalent English Proverbs" (ismail4all.wordpress.com, 2013)
The source explains it: Speech is silver, silence is gold.
. The wording of the meaning is ours.