Jesus said, “Take up your cross.” Is He saying how He will be murdered – on a cross? If so, how did He know that?
Yes, Jesus knew that He would die – even the death of the cross. He is walking towards Jerusalem in the shadow of the cross event looming ahead. He is willingly offering His life as a sacrifice. He came for this purpose. We needed a Savior.
Jesus did not just know about how He would die. He orchestrated the entire event. Jesus is not simply a God who can “look into the future.” He is unfolding history as the Sovereign King who is unfolding his eternal purposes.
Read all of passages like Psalm 22, written a thousand years before the cross – when that method of torturous death didn’t even exist – where it says things like:
 I am poured out like water,
and all my bones are out of joint;
my heart is like wax;
it is melted within my breast;
 my strength is dried up like a potsherd,
and my tongue sticks to my jaws;
you lay me in the dust of death.
 For dogs encompass me;
a company of evildoers encircles me;
they have pierced my hands and feet—
 I can count all my bones—
they stare and gloat over me;
 they divide my garments among them,
and for my clothing they cast lots.
(Psalm 22:14-18 ESV)
And remember, it was Jesus’ enemies who actually brought about the fulfillment of these prophecies.
Isaiah 53 is dramatically clear – written some 800 years before Jesus was crucified.
 Surely he has borne our griefs
and carried our sorrows;
yet we esteemed him stricken,
smitten by God, and afflicted.
 But he was pierced for our transgressions;
he was crushed for our iniquities;
upon him was the chastisement that brought us peace,
and with his wounds we are healed.
 All we like sheep have gone astray;
we have turned—every one—to his own way;
and the LORD has laid on him
the iniquity of us all.
 He was oppressed, and he was afflicted,
yet he opened not his mouth;
like a lamb that is led to the slaughter,
and like a sheep that before its shearers is silent,
so he opened not his mouth.
 By oppression and judgment he was taken away;
and as for his generation, who considered
that he was cut off out of the land of the living,
stricken for the transgression of my people?
 And they made his grave with the wicked
and with a rich man in his death,
although he had done no violence,
and there was no deceit in his mouth.
 Yet it was the will of the LORD to crush him;
he has put him to grief;
when his soul makes an offering for guilt,
he shall see his offspring; he shall prolong his days;
the will of the LORD shall prosper in his hand.
 Out of the anguish of his soul he shall see and be satisfied;
by his knowledge shall the righteous one, my servant,
make many to be accounted righteous,
and he shall bear their iniquities.
 Therefore I will divide him a portion with the many,
and he shall divide the spoil with the strong,
because he poured out his soul to death
and was numbered with the transgressors;
yet he bore the sin of many,
and makes intercession for the transgressors.
(Isaiah 53:4-12 ESV)
There are foreshadowings all through the Old Testament Scriptures of Jesus who is called “The Lamb slain from the foundation of the world.” This was the redemptive plan of God – for our salvation and joy and His glory and delight.
 this Jesus, delivered up according to the definite plan and foreknowledge of God, you crucified and killed by the hands of lawless men.  God raised him up, loosing the pangs of death, because it was not possible for him to be held by it.
(Acts 2:23-24 ESV)
 for truly in this city there were gathered together against your holy servant Jesus, whom you anointed, both Herod and Pontius Pilate, along with the Gentiles and the peoples of Israel,  to do whatever your hand and your plan had predestined to take place.
(Acts 4:27-28 ESV)
When Jesus “blew down” the soldiers come to arrest Him by simply saying His God name – “I Am” – He was displaying that no one was taking His life from Him. Jesus was giving His life for the sins of the world. Jesus was the one in authority that day.
Thus the Psalmist referring to the day of the cross sang, “This is the day that the Lord has made, let us be glad and rejoice in it.” Because of that day on the cross – this day is a day of salvation!