Sunday's second reading (Phil 2: 6-11) contains the key for understanding not only the other two passages, but all of Holy Week.
The only problem is that most of us rarely hear these lines as Paul originally intended them to be heard. We usually filter this ancient Christian hymn through a theology not yet in vogue when Philippians was composed.
The most misinterpreted part of the section is its opening statement: "Christ Jesus, though He was in the form of God, did not regard equality with God something to be grasped. Rather, He emptied Himself, taking the form of a slave, coming in human likeness; and found human in appearance, He humbled Himself, becoming obedient to the point of death, even death on a cross."
Almost everyone hears those words against the backdrop of John's Christology. From his Gospel's famous prologue, we know John believes Jesus is a person who always existed as God; but, at a definite point in our history, He came down to earth and was born a human. This is how most of us interpret the phrase, "He emptied Himself."
Though we learned John's "God-to-earth" Christology from our grade school catechisms, scholars believe this way of understanding Jesus' divinity and humanity first evolved in the Church toward the end of the first century, 40 years after Paul wrote his letter to the community at Philippi. The earliest authors of the Christian Scriptures seem to know nothing of Jesus' pre-existence. They're more concerned with what Jesus does here than in what He did or who He was before He got here.
It's possible then that when Paul speaks about someone imitating Jesus who "emptied Himself," he's referring not to the divine things Jesus gave up to come among us on this earth, but to the natural human things He renounced while He historically was in our world.
When the Apostle mentions Jesus being in the "form of God," or speaks about His "equality with God," he's probably thinking about the theology of the Genesis author who believes humans are created in "God's image and likeness."
Paul contends that Jesus emptied Himself or such divine prerogatives during His earthly life and accepted the condition of the most menial human: a slave. This emptying both leads to Jesus being acclaimed as God and is the basis for our imitating Him. Christians are called to become completely one with the most rejected person in their communities.
But in order to discover the day-by-day particulars of that call, they're expected to imitate Deutero-Isaiah, believing God "morning after morning opens their ears so they may hear" (Is 50: 4-7). No matter the physical or psychological pain, they're constantly to press ahead in this endeavor, confident that, with God's help, they'll "never be put to shame."
Hearing Luke's passion narrative from this perspective (Lk 22: 14-23:56), we more clearly understand how we're to empty ourselves for others. Notice, for instance, how many times Luke's Jesus zeroes in on other people's pain while He Himself is experiencing much worse. This is the only Gospel in which He heals the guard's ear, comforts the women who are trying to comfort Him and forgives one of the thieves crucified with Him.
It's no accident that a scribe, making a copy of Luke's Gospel long after he wrote it, added the famous line, "Father, forgive them. They know not what they're doing." This is the one Gospel into which it perfectly fits.
Luke never intends us just to look at Jesus' suffering from an historical perspective. His goal is to help us reflect on what pain is necessary in our own lives before we cant truly become one with those around us.
As I mentioned above, such emptying is what Holy Week is all about. If we don't experience it, Easter becomes just a day for hunting eggs.