Branch - Better, leaf, as in Psalm 1:3; Isaiah 34:4.

He that trusteth in his riches shall fall,.... As leaves in autumn, which are withered and dry. To trust in riches is to trust in uncertain things; things not to be depended on, being here today and gone tomorrow; it is like leaning upon a broken staff, which giving way, the person falls: and so the fall of Babylon will be, while she is trusting in and boasting of her riches and grandeur, Revelation 18:7;
but the righteous shall flourish as a branch; that abides in the tree, is alive and green, full of leaves, and laden with fruit: so the righteous are as branches in Christ, and receive life and nourishment from him, and abide in him; and bring forth fruit and flourish, like palm trees and cedars, in the house of the Lord, and grow in every grace, and in the knowledge of Christ; see Jeremiah 17:7.

The true believer is a branch of the living Vine. When those that take root in the world wither, those who are grafted into Christ shall be fruitful.

(Compare Proverbs 10:15; Psalm 49:6; 1-Timothy 6:17).
righteous . . . branch-- (Psalm 1:3; Jeremiah 17:8).

28 He that trusteth in his riches shall fall,
And the righteous shall flourish like the green leaf.
יפּול (plene after the Masora) as well as the figure וכעלה (cf. for the punctuation וכעשׁן, Proverbs 10:26) are singular, but are understood if one observes that in 28a a withered tree, and in 28b a tree with leaves ever green, hovers before the imagination of the poet (cf. Psalm 1:4; Jeremiah 17:8). The proud rich man, who on the ground of his riches appears to himself to be free from danger, goes on to his ruin (יפול as Proverbs 11:5, and frequently in the Book of Proverbs), while on the contrary the righteous continues to flourish like the leaf - they thus resemble the trees which perennially continue to flourish anew. Regarding עלה as originally collective (Symm. θάλλος), vid., at Isaiah 1:30, and regarding פּרח (R. פר, to break), here of the continual breaking forth of fresh-growing leaf-buds, vid., at Isaiah 11:1. The apostolic word names this continual growth the metamorphosis of believers, 2 Cor. 2:18. The lxx has read וּמעלה (approved by Hitzig): and he who raiseth up the righteous.