Who. ? Figure of speech Erotesis. The questions are asked by the prophet, and the answer is "no one" or few. Quoted in John 12:38 and Romans 10:16.
hath believed. put faith in. Hebrew. aman. App-69. The tenses are Past (the prophetic Perfect).
report. hearing. Put by Figure of speech Metonymy (of Adjunct), for the subject-matter, which was heard.
arm. Put by Figure of speech Metonymy (of Cause), for what was wrought by it. Compare Isaiah 51:9; Isaiah 52:10.
the Lord. Hebrew. Jehovah. App-4.
revealed. made bare: i.e. revealed.