Romans 11:33–36 is Paul’s poetic, hymn-like praise of God and His amazing wisdom. He quotes Old Testament texts such as Isaiah and Job. The prior passage explained how God’s intent for Israel came with some level of mystery. As limited, created people, we will never be able to fully grasp the mind of God. The proper response, when we realize how beyond our understanding He is, is praise and worship.
For a more detailed summary select the link below.
“Romans 11:33” Bibleref.com
33 Oh the depth of the riches both of the wisdom and the knowledge of God! How unsearchable are his judgments, and his ways past tracing out!