23:15-25 It is honourable to shelter and protect the weak, provided they are not wicked. Proselytes and converts to the truth, should be treated with particular tenderness, that they may have no temptation to return to the world. We cannot honour God with our substance, unless it be honestly and honourably come by. It must not only be considered what we give, but how we got it. Where the borrower gets, or hopes to get, it is just that the lender should share the gain; but to him that borrows for necessary food, pity must be showed. That which is gone out of thy lips, as a solemn and deliberate vow, must not be recalled, but thou shalt keep and perform it punctually and fully. They were allowed to pluck and eat of the corn or grapes that grew by the road side; only they must not carry any away. This law intimated what great plenty of corn and wine they should have in Canaan. It provided for the support of poor travellers, and teaches us to be kind to such, teaches us to be ready to distribute, and not to think every thing lost that is given away. Yet it forbids us to abuse the kindness of friends, or to take advantage of what is allowed. Faithfulness to their engagements should mark the people of God; and they should never encroach upon others.
24, 25. When thou comest into thy neighbour's vineyard, then thou mayest eat grapes thy fill at thine own pleasure—Vineyards, like cornfields mentioned in the next verse [De 23:25], were often unenclosed. In vine-growing countries grapes are amazingly cheap; and we need not wonder, therefore, that all within reach of a person's arm, was free; the quantity plucked was a loss never felt by the proprietor, and it was a kindly privilege afforded to the poor and wayfaring man.