The following are not sermons but I believe they are helpful. One is a debate review. The other is a book review (with helpful illustrations). Both discuss and defend the paedobaptist view of the meaning and implications of Jeremiah 31 and the New Covenant in the practice of baptism. Both are well-written and go right at the heart of the issue.
The ideas discussed by the two I believe are the same ones that would appear in any sermon of a paedobaptist minister on the topic of baptism. Blessings!