Augustine of Hippo

"O fear the Lord, all you His saints, for there is no want to them that fear Him" [Psalm 34:9]. For many therefore will not fear God the Lord, lest they suffer hunger. It is said to them, Defraud not; and they say, Whence can I feed myself? No art can be without imposture; no business can be without fraud. But fraud God punishes: fear God. But if I should fear God, I shall not have whence to live. …

Exposition on Psalm 34 ↗

Thomas Aquinas

Then when he says, "Fear," he first exhorts to the observance of divine fear. Second, he assigns the cause of fear, at "For there is no want." Third, he makes the cause manifest, at "The rich have been in need." He says therefore, "The Lord is sweet and gentle." But to whom? To those who fear him. Therefore, "Fear the Lord, all you his saints." And he says "saints," because no one can be holy unless he is God-fearing. …

Exposition on the Psalms of David ↗

Bonaventure

By the authority of the Psalm: Fear the Lord, all you his saints, for there is no want to those who fear him: therefore being in want and fearing God do not stand together. To that which is first objected to the contrary, that there is no want to those who fear God — it must be said that want is twofold, namely bodily and spiritual: but that word is understood not of any want whatsoever, but of spiritual want. …

Disputed Questions on Evangelical Perfection, Question 2 ↗