For the scripture saith - in Isa 28:16, a glorious Messianic passage.
Whosoever believeth on him shall not be ashamed - Here, as in Rom 9:33, the quotation is from the Septuagint, which renders those words of the original, “shall not make haste” (that is, fly for escape, as from conscious danger), “shall not be put to shame,” which comes to the same thing.