The concept of boasting is taken here in the sense of a joyful feeling that elevates the Christian’s consciousness, yet remains humble.
It is a feeling of God’s good will toward man for the measure in which he fulfills the will or decree of God; compare Rom 5:3, 2 Cor 11:30, Gal 6:14 and parallels.
This is boasting in the Lord, or in the Lord. The highly developed moral feeling of the Christian especially boasts in afflictions, regarding them as the work of God’s good will and mercy (Rom 5:3 and parallels).
The concept of “lowly,” properly “humble,” is taken in the sense of poor, needy, deprived of the goods of outward life. To him the rich man is opposed, since he possesses these goods in abundance.
The wisdom from God teaches the Christian that, if he is poor and humbled in this poverty, but bears this poverty and humiliation as befits a Christian, according to the law of Christ, he is not lowly, but exalted.
He bears it with joy (v. 1) and thanksgiving to God for the sending of this temptation. Therefore he may boast in the Lord of this exaltation, as of God’s mercy toward him.
On the contrary, if the rich man can boast, it is by no means in his wealth, but likewise in his poverty or humiliation, if he can acquire this poverty or humiliation.
According to the Christian law, the highest degree of perfection for the rich man is to sell his possessions and distribute them to the poor (Mt 19:21; compare the note).
If he does not have the strength to do this, then at least he is obliged to use his wealth as he ought and to look upon it properly.
He must acquire poverty of spirit, and only in this may he boast in the Lord, if he can boast at all, but by no means in his wealth.
For what is the rich man, if he does not have this correct Christian view of wealth, if he does not use it rightly, and if he does not have this poverty of spirit?
The Apostle expressively and graphically compares him to the flower of the grass because of how quickly he passes, and therefore because of his nothingness; compare Theophylact.
This is especially vivid in the hot, burning countries of the East, such as Palestine, where the heat of the sun quickly dries up the grass of the field.
“So also the rich man withers in his ways.” The rich man who uses his wealth for comfort and the delight of his life is beautiful in appearance, like a field flower.
But wealth is a thing just as unstable and quickly passing as a field flower. The heat will come, some unexpected calamities will descend; compare Job ch. 1. Then the wealth has perished.
Even if calamities do not overtake the rich man, death will overtake him sooner or later, and there is an end of wealth. And is the whole life of man long, even if he is old?
It is a vapor that appears for a little time and then vanishes (Jas 4:14). In both cases the rich man withers like a flower, and all his ways, all his undertakings and actions, come to an end; compare Theophylact.
If he had nothing besides wealth, then he has nothing in which to boast. Therefore he may boast only in his abasement, if he has acquired it in wealth or through wealth.