This is an older book, but I really relish reading it. I grew up around cattle, not sheep. While they are both livestock, they are managed a little differently. Keller's book is full of insight into the beloved 23rd Psalm. It's broken into 12 chapters, devoting two chapters to each verse in the poem. The reader with really meditate on this Psalm. It also gave me insight to other passages in the Bible that discuss the Shepherd/sheep relationship. I highly recommend it as background reading for John 10 in which Jesus tells His followers "I am the good shepherd." Pick up a used copy at a garage sale and enjoy!