"The race is not always to the swift, nor the battle to the strong; and those who are diligent in business may not always be prospered. But it is “the hand of the diligent” that “maketh rich.” And while indolence and drowsiness grieve the Holy Spirit and destroy true godliness, they also tend to poverty and want. “He becometh poor that dealeth with a slack hand.” Proverbs 10:4 . CT 278.1"
"He becometh poor that dealeth with a slack hand: but the hand of the diligent maketh rich."
EGW quotes Proverbs 10:4 directly, making this an explicit allusion and a direct principle.
"I returned, and saw under the sun, that the race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favour to men of skill; but time and chance happeneth to them all."
EGW directly alludes to Ecclesiastes 9:11, quoting the first part of the verse. While not a direct principle, the allusion is clear and supports her point about diligence.
"Judicious labor is a healthful tonic for the human race. It makes the feeble strong, the poor rich, the wretched happy. Satan lies in ambush, ready to destroy those whose leisure gives him opportunity to approach them under some attractive disguise. He is never more successful than when he comes to men in their idle hours. CT 278.2"
"Put on the whole armour of God, that ye may be able to stand against the wiles of the devil."
The connection is valid. EGW's statement about Satan lying in ambush and being successful in idle hours thematically aligns with Ephesians 6:11, which encourages believers to be prepared against the wiles of the devil. Both passages highlight the need for vigilance against spiritual attacks.