Gave the sense. — They expounded obscurer passages, and in doing so naturally translated into the vernacular Aramaic dialect.
Caused them to understand the reading. — This simply explains the former: they expounded as they read.
Related Commentaries of Nehemiah 8:8
Nehemiah 8:8
8 So they read in the book in the law of God distinctly, and gave the sense, and caused them to understand the reading.