The "liar" is probably the man, who makes false excuses for not giving, and so is inferior to the poor man, whose "desire," the wish to do good, is taken, in the absence of means to carry it into effect, for the act of kindness itself.

The desire of a man [is] his (h) kindness: and a poor man [is] better than a liar.
(h) That is, that he be honest: for the poor man who is honest is to be esteemed above the rich who is not virtuous.

The desire of a man is his kindness,.... Either the grace and kindness of God, which is, desirable by every sensible man, as being most excellent, and better than life and anything in it; or it is his desire to show kindness. A good man is desirous of riches, that he might have it in the power of his hands to do good to others; and a beneficent man, who has it in his power, is desirous of an opportunity of showing kindness to his fellow creatures and friends; and such a disposition and conduct render a man very desirable and amiable; it is the beauty of a man, as Ben Melech; yea, a man that is not able to do a kindness to another, yet has a desire to do it, his good will is his kindness, and the will is taken for the deed. Gersom takes the word in the sense of "reproach", as it is sometimes used; and understands it of the sinful desires of the heart, the imaginations of the thoughts of the heart, which are evil continually, and so matter of reproach;
and a poor man is better than a liar; who is a rich man, as the Septuagint and Syriac versions add; who denies that he has ability to relieve the poor, when he has; or promises to do it, and does it not; such men of high degree are a lie indeed! and the poor man, whom he should relieve, is a better man than he; or that would relieve another, but it is not in his power to do it.

It is far better to have a heart to do good, and want ability for it, than to have ability for it, and want a heart to it.

desire--that is, to do good, indicates a kind disposition (Proverbs 11:23); and the poor thus affected are better than liars, who say and do not.

The series makes a new departure with a proverb regarding the poor (cf. Proverbs 19:17):
A man's delight is his beneficence;
And better is a poor man than a liar.
The right interpretation will be that which presses upon תּאות no strange meaning, and which places the two parts of the verse in an inner mutual relation ethically right. In any case it lies nearer to interpret תאות, in relation to man, actively than passively: that which makes man worthy of desire (Rashi), adorns and distinguishes him (Kimchi, Aben-Ezra); or, that which is desired by man, is above all things sought for (Luzzatto); and, in like manner, the Hebrews. meaning for חסדּו lies nearer than the Aram. (vid., Proverbs 14:34): the pleasure of a man is his disgrace (Ralbag). Thus Bertheau's translation: the desire of a man is his charitas, must mean: that which brings to a man true joy is to act amiably. But is that, thus generally expressed, true? And if this were the thought, how much more correctly and distinctly would it be expressed by שׂמחה לאדם עשׂות חסד (cf. Proverbs 21:15)! Hitzig so rightly reminded by חסדו of the Pharisee who thanks God that he is not as other men; the word ought to have been חסד to remove every trace of self-satisfaction. Hitzig therefore proposes from the lxx and the Vulgate the text-correction מתּבוּאת no, and translates, "from the revenue of a man is his kind gift;" and Ewald, who is satisfied with תּבוּאת, "the gain of a man is his pious love." The latter is more judicious: חסד (love) distributed is in reality gain (according to Proverbs 19:17); but 22b corresponds rather with the former: "better is he who from want does not give תבואה, than he who could give and says he has nothing." But was there then need for that καρπός of the lxx? If a poor man is better than a lord given to lying - for אישׁ with רשׁ is a man of means and position - i.e., a poor man who would give willingly, but has nothing, than that man who will not give, and therefore lies, saying that he has nothing; then 22a means that the will of a man (cf. תאות, Proverbs 11:23) is his doing good (vid., regarding חסד, ad Proverbs 3:3), i.e., is its soul and very essence. Euchel, who accordingly translates: the philanthropy of a man consists properly in his goodwill, rightly compares the Rabbinical proverb, אחד המרבה ואחד הממעיט ובלבד שׁיתבוון, i.e., one may give more or less, it all depends on the intention, the disposition.

The desire - The hearty desire of being kind is accepted by God, and should be owned by men as a real kindness. A poor man - Who is not able to give what he desires to do. A liar - Than a rich man who feeds the poor with fair promises, but doth not perform what he pretends.