The author needs to explain why He chose for the wise men gave Him gold, frankincense and myrrh. (all very valuable at that time)
Or why Jesus wore underwear too valuable to tear (unlike his outer garments)...
Then the soldiers, when they had crucified Jesus, took His outer garments and made four parts, a part to every soldier and also the tunic; now the tunic was seamless, woven in one piece.So they said to one another, "Let us not tear it, but cast lots for it, to decide whose it shall be"; this was to fulfill the Scripture: "THEY DIVIDED MY OUTER GARMENTS AMONG THEM, AND FOR MY CLOTHING THEY CAST LOTS."