#1 - To Prove Lazarus was Dead
Some speculate the timing was about belief the soul hovered around the body for 3-days after death:
A state of death beyond the third day meant, from popular Jewish point of view, an absolute dissolution of life. At this time the face cannot be recognized with certainty; the body bursts; and the soul, which waited until then hovered over the body, parts from it.1
However, if the text serves as a guide, the reason is to prove Lazarus was physically dead:
Jesus said, “Take away the stone.” Martha, the sister of the dead man, said to him, “Lord, by this time there will be an odor, for he has been dead four days.” (John 11:39) [ESV]
There are 4 stages of human decomposition: autolysis, bloat, active decay, skeletonization. Here is a brief description of the first two:2
Autolysis (24-72 hours) - begins immediately after death. As soon as blood circulation and respiration stop, the body has no way of getting oxygen or removing wastes. Excess carbon dioxide causes an acidic environment, causing membranes in cells to rupture. The membranes release enzymes that begin eating the cells from the inside out.
Bloat (3-5 days) - Leaked enzymes from the first stage begin producing many gases. The sulfur-containing compounds that the bacteria release also cause skin discoloration. Due to the gases, the human body can double in size. In addition, insect activity can be present. The microorganisms and bacteria produce extremely unpleasant odors called putrefaction. These odors often alert others that a person has died, and can linger long after a body has been removed.
Regardless of any custom or belief, is the common knowledge of the physical state of a body which has been dead for at least 4-days. Martha states what everyone knows: Lazarus has been dead long enough for the normal decaying process to produce gases typical to a decaying body. Therefore by waiting 2-days in order to arrive at the tomb on the fourth day, Jesus has ensured no one can question Lazarus was dead and his resurrection can only be attributed as a miracle.
#2 - To Show How Days are Counted
John makes two statements of time. First, Jesus waited for 2-days. Second, Martha states Lazarus had been dead 4-days when Jesus arrives. How are these two periods to be understood? If they are separate, the entire episode covers 6-days; if they are concurrent, the minimum period is 4-days:
Separate = 6-days total Concurrent = 4 days total
2-days waiting + 4 days dead 2-days waiting
4-days dead
Implies 4-days to reach Bethany Implies 2-days to reach Bethany
I believe the key to the day of Lazarus' death comes from a statement both Martha and Mary make:
Martha said to Jesus, “Lord, if you had been here, my brother would not have died. (11:21)
Now when Mary came to where Jesus was and saw him, she fell at his feet, saying to him, “Lord, if you had been here, my brother would not have died.” (11:32)
The simplest way to understand their reaction is to take the text literally: Lazarus died almost immediately after Martha and Mary sent their message. They knew it was impossible for Jesus to have received their message before Lazarus died. They have great faith. They know Jesus does not have to be present to heal. They know the blind man received his sight not when Jesus touched him, but later when he washed. They know He healed a child in Cana while He was in Capernaum. They know all they needed to do is to make Jesus aware of the illness and Lazarus would live. But, death came too quickly. Their message did not arrive before Lazarus died.
They are not complaining Jesus did not come sooner. They are simply stating a fact. From their perspective the only way Lazarus could have lived is if Jesus had been there (when he became ill). In this case Lazarus died and was entombed on the same day they sent their message. In fact, Lazarus was dead when it arrived:
Day 1: Lazarus is sick
Day 1: Martha and Mary send a messenger (who reaches Jesus later on this day)
Day 1: Lazarus dies and is placed in the tomb
Day 1: Jesus "heals" Lazarus (his body does not decay or become rigid)
+ 2-days - Jesus waits
+ 1-day - Jesus travels to and arrives in Bethany and frees Lazarus from the tomb
-------
4-days - Lazarus was "dead"
Because of the "delay," John is able to explain how the 2-days of waiting were counted:
So, when he heard that Lazarus was ill, he stayed two days longer in the place where he was. Then after this he said to the disciples, “Let us go to Judea again.” The disciples said to him, “Rabbi, the Jews were just now seeking to stone you, and are you going there again?”Jesus answered, “Are there not twelve hours in the day? If anyone walks in the day, he does not stumble, because he sees the light of this world. (11:6-9)
In order for Lazarus to have been dead for 4-days, Jesus had to wait two full days, which included two 12-hour periods of daylight.
Notes:
1. Gustaf Dalman, Jesus-Jeshua, Studies in the Gospels, translated by Paul P. Levertoff, Kessinger Publishing, LLC, 2008, p. 220 [citing Eccl. R. 12.6; Lev. R. 18.1]
2. The Four Stages of Human Decomposition.
