BeginningWithMoses.org) pointed me to Donald McLeod's The Person of Christ, p174-175:
“Here is a man pouring his whole strength, physical and spiritual, into a plea that God would save him. It is clear from all the accounts that Jesus’ experience of turmoil and anguish was both real and profound. His sorrow was as great as a man could bear, his fear convulsive, his astonishment well-nigh paralyzing. He came within a hairsbreadth of break-down. He faced the will of God as raw holiness, the mysterium tremendum in its most acute form: and it terrified him….
…What Christ saw in Gethsemane was God with the sword raised… the sight was unbearable… in a few short hours… he would stand before that God answering for the sin of the world: indeed, identified with the sin of the world. He became as Luther said, ‘the greatest sinner that ever was’ Consequently, to quote Luther again, ‘No-one ever feared death so much as this man’. He feared it because for him it was no sleep but the wages of sin; death with the sting; death unmodified and unmitigated; death as involving all that sin deserved. He, alone, would face it without a covering providing by his very dying the only covering for the world, but doing so… totally exposed to God’s abhorrence of sin. And he would face death without God..… deprived of the one solace and the one resource which had always been there….
The wonder of the love of Christ for his people is not that for their sake he faced death without fear, but that for their sake he faced it terrified. Terrified by what he knew, and terrified by what he did not know, he took damnation lovingly…
…what he faced at Gethsemane we shall never face; and we shall never face it precisely because he faced it, offering his body as the place where God should effect the condemnation of sin. Gethsemane is as unique as Calvary because, as much as the cross, it belongs not to church history but to salvation history."