Can you find the plan of salvation or the Gospel in the Old Testament?
No. The Old Testament does not contain the Gospel or the plan of salvation; at most it provides a picture of it. Paul says those things written beforehand were written for our learning, not our doctrine. The Old Testament is the bedrock for the New, and understanding it increases hope.
Les explains from Romans 15:4 that whatsoever things were written aforetime—the Old Testament—were written for our learning. Even though it was written to the Jew under the Law, it is still for our learning. He emphasizes that you will not find the plan of salvation back in Exodus; you will find a picture of it, but you will not find the Gospel in Exodus or anywhere else in the Old Testament. The Old Testament is the bedrock for the New, and you cannot understand the New unless you understand the Old. It is there for our learning so that through patience and comfort of the Scriptures we might have hope.