you understand better by seeing for yourself than hearing about it, seeing is believing
köken: Calque of Classical Chinese 百聞不如一見 (bǎi wén bùrú yī jiàn, literally “Hearing a hundred times is not as good as seeing once”). From the Book of Han.
picture is worth a thousand words · seeing is believing
köken: Calque of Russian лу́чше оди́н раз уви́деть, чем сто раз услы́шать (lúčše odín raz uvídetʹ, čem sto raz uslýšatʹ), in turn a calque of Chinese 百聞不如一見 /百闻不如一见 (bǎi wén bùrú yī jiàn, “it's better to see once than hear a hundred times”).