"This scene was presented before me to illustrate the selfish love of slavery, and the desperate measures which the South would adopt to cherish the institution, and the dreadful lengths to which they would go before they would yield. The system of slavery has reduced and degraded human beings to the level of the brutes, and the majority of slave masters regard them as such. The consciences of these masters have become seared and hardened, as was Pharaoh's; and if compelled to release their slaves, their principles remain unchanged, and they would make the slave feel their oppressive power if possible. It looked to me like an impossibility now for slavery to be done away. God alone can wrench the slave from the hand of his desperate, relentless oppressor. All the abuse and cruelty exercised toward the slave is justly chargeable to the upholders of the slave system, whether they be Southern or Northern men. 1T 266.1"
"But when Pharaoh saw that there was respite, he hardened his heart, and hearkened not unto them; as the Lord had said."
EGW explicitly mentions Pharaoh and his hardened heart, directly connecting the slave masters' behavior to Pharaoh's resistance to releasing the Israelites.
"And even as they did not like to retain God in their knowledge, God gave them over to a reprobate mind, to do those things which are not convenient;"
EGW describes the slave masters' consciences as seared, leading them to dehumanize slaves. Romans 1:28 describes a similar process of rejecting God and being given over to a reprobate mind. The connection is thematic, though not explicit.
I had a view of the disastrous battle at Manassas, Virginia. It was a most exciting, distressing scene. The Southern army had everything in their favor and were prepared for a dreadful contest. The Northern army was moving on with triumph, not doubting but that they would be victorious. Many were reckless and marched forward boastingly, as though victory were already theirs. As they neared the battlefield, many were almost fainting through weariness and want of refreshment. They did not expect so fierce an encounter. They rushed into battle and fought bravely, desperately. The dead and dying were on every side. Both the North and the South suffered severely. The Southern men felt the battle, and in a little while would have been driven back still further. The Northern men were rushing on, although their destruction was very great. Just then an angel descended and waved his hand backward. Instantly there was confusion in the ranks. It appeared to the Northern men that their troops were …
"Pride goeth before destruction, and an haughty spirit before a fall."
The EGW passage describes the Northern army's boastful advance and subsequent defeat, which aligns with the proverb about pride preceding a fall. The connection is thematic, not a direct quote or explicit allusion.