With a mast on his shoulder, Santiago had to rest five minutes on his way home in The Old Man and the Sea. What is the symbolic reference?

Hemingways writes, on pg. 120:

Finally he put the mast down and stood up. He picked the mast up and put it on his  shoulder and started up the road. He had to sit down five times before he reached his shack.

Obviously the way Santiago carries the mast is symbolic of the way Jesus carried the cross.  Both are emblems of suffering.

Why does Santiago have to sit down 5 times?

Five is a symbolic number: first, it represents the five wounds Christ received on the cross:

• Two of the wounds were through either his hands or his wrists, where nails were inserted to fix Jesus to the cross-beam of the cross on which he was crucified.


• Two were through the feet where the nail(s) passed through both to the vertical beam.


• The final wound was in the side of Jesus' chest, where, according to the New Testament, his body was pierced by a lance in order to be sure that he was dead. The Gospel of John (19:34) states that blood and water poured out of this wound.

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  The five parts of the clothing remaining of Jesus during his crucifixion after the soldiers had made four parts of his dress, plus his tunic which they did not tear. (Jn 19,23)

  
  


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  Saint Paul declares that by five times he received the 39 lashes from the Jews. (2 Co 11,24)

  
  

Also, five is a symbol of man.  Remember the Pixies' song "This Monkey's Gone to Heaven" where Frank Black sings "Man is five; the devil is six...and God is seven"?  Here's more:

The number 5 is a characteristic of the man. First, according to the Cabal, it is the number of the perfect Man (got rid from his animal side). According to the Bible, it is the symbol of the Man-God by the five wounds of the Christ on cross (for this reason, it is also considered as the number of the grace). But it is also associated to the man in general (2 + 3) having an unstable character of duality, 2, in spite of his divinity, 3. The 5 is also found on the human body: the five fingers of the hand and feet, the five senses (touch, taste, sense of smell, hearing and the sight), the five members (two arms, two legs and the head, the bust being the center), the five bones forming the metacarpus, the metatarse and the brain-pan, etc.