The sefer Chovos haLevavos (Duties of the Heart) is organized into ten shaarim ("gates"). This is not by chance, and these ten can actually be linked with the ten makkos (plagues) of Egypt. The last gate of Chovos haLevavos is Shaar Ahavas Hashem, the Gate of Love of Hashem, whereas the last plague was the smiting of the firstborn. What exactly is the connection?
Let's start like this: The Brisker Rav z"l said that the first nine plagues were actually of a different nature from plague number ten. The first nine, he explains, were a form of judgement and punishment of the Mitzri'im for their mistreatment of the Yidden, like Hashem had told Moshe (as Rashi explains): "Behold I have made you a judge and punisher (elohim) to Paroh" (7:1). Plague number ten, however, was different: it was specifically intended to bring Paroh to free us, like when Paroh is told way from the beginning to "send us out and if not the firstborns will be smitten" (4:23).
Ok, so we've got this down—plague number ten was to get us freed. Now back to where we started: What does this have to do exactly with the tenth section of Chovos haLevavos, which focuses on love of Hashem?
We can suggest that the concept of ahavas Hashem is not just another piece in the puzzle in the service of Hashem, but rather the final connection with Hashem that surmounts everything and makes the parts a whole—the glue. It is what frees us from the mud, and sends us flying towards Hashem, higher and higher.
Story:
Elisha* was desperate for a yeshua (salvation) in a certain area, so he called up a big baal bitachon (someone who specializes in closeness to Hashem) for a beracha (blessing). He didn't get through, so he just left a message. Hashem saw that he was trying, and in turn gave Elisha an even bigger miracle than expected, better than ever. Elisha is still getting over the "shock" of the greatness of the mofeis (wonder).
