Earlier quoted context omitted.
Hard to convey and even more concise in Chinese, e.g. 道可道, 非常道. (Characters respectively mean: {'道[1]': 'Tao', '可': 'can; able', '道[2]': 'say; tell', '非': 'not', '常': 'usual; normal', '道[3]': 'Tao'}).
'道[2]' did not have the meaning of 'say; tell' until the Song dynasty, which was ~1000 years ago. Therefore, it is questionable, whether the second '道' really means 'say; tell' in the text before 2000 years.
If so, '道' initially means 'path; road', and its further meaning 'law; principle' can indicate its alternative function in the sentence (n. -> v.). It might be 'describe; illustrate' rather than 'say' here.