A Bible Commentary aims to help the reader understand the text of the Bible. They are most useful as a reference text once you have worked at the passage/s yourself.
Thanks to The Gospel Coalition, here is a site which offers commentaries which are trustworthy, scholarly, accessible and free on every book of the Bible.
You will find commentaries on every book of the Bible, as well as introductions to the New and Old Testaments, Paul’s letters, the Gospels, and much more. Whether you are a ministry leader, a Bible teacher, or are searching for resources to help in your own reading and understanding of Scripture, these commentaries will be a great help.