This commentary by Cornelius a Lapide is absolutely astonishing. It is packed with great information on the four Gospels and is a four-volume set. Originally written in Latin in the early 17th century, it is the best Biblical commentary I have ever seen. It's a bit pricey but the contents are well worth the price. You can purchase it here.

Here is some info from the Loreto website.
This set boasts the following features:

* Leather Covers & Satin Ribbons
* 2800+ Pages in Four Volumes
* Never Fully Translated Before
* Sewn Binding & Headbands
* First of over 30+ volumes to come
* A percentage of sales goes to further translations of other volumes
* Extensive discussion of Greek & Hebrew word meanings