I shall not want

The same verb describes Israel gathering manna: 'he that gathered much had nothing over, and he that gathered little had no lack' (Exodus 16:18). Nobody in that story got rich. Everybody got fed.

Moses later summarises forty years with the same idea: 'thou hast lacked nothing' (Deuteronomy 2:7). The word therefore arrives in Psalm 23 already carrying a history of daily bread rather than surplus.

The confidence in the second half rests entirely on the identity in the first. Because the LORD is the shepherd, the sheep will not lack. Detach the two and the line becomes a positive-thinking slogan, and it will break the first time a real need is not met on schedule.

Notice too what the psalm counts as provision when it gets specific: grass, drinkable water, a recovered soul, a right path, company in the dark, a table, oil, and a home. Not one of those is money.

David wrote parts of his life in caves. Paul, who quoted the psalms constantly, learned to be content both full and hungry (Philippians 4:11-12). The verse does not exempt anyone from want in the ordinary sense of wanting things. It promises that the shepherd will not fail to supply what the sheep actually needs to arrive home.

This is why the psalm can hold verse 1 and verse 4 in the same poem without contradiction. Sufficiency is not the same as ease.