Charles H. Spurgeon on Psalms 35:5

"Let them be as chaff before the wind." They were swift enough to attack, let them be as swift to flee. Let their own fears and the alarms of their consciences unman them so that the least breeze of trouble shall carry them hither and thither. Ungodly men are worthless in character, and light in their behaviour, being destitute of solidity and fixedness; it is but just that those who make themselves chaff should be treated as such. When this imprecation is fulfilled in graceless men, they will find it an awful thing to be for ever without rest, without peace of mind, or stay of soul, hurried from fear to fear, and from misery to misery. "And let the angel-of the Lord chase them." Fallen angels shall haunt them, good angels shall afflict them. To be pursued by avenging spirits will be the lot of those who delight in persecution. Observe the whole scene as the Psalmist sketches it: the furious foe is first held at bay, then turned back, then driven to headlong flight, and chased by fiery messengers from whom there is no escape, while his pathway becomes dark and dangerous, and his destruction overwhelming.