Let thy fountain be blessed,.... Thy wife; make her happy by keeping to her and from others; by behaving in a loving, affable, and respectful manner to her; by living comfortably with her, and providing well for her and her children: or reckon her a happiness, a blessing that God has bestowed; or "thy fountain shall be blessed,'' as the Targum; that is, with a numerous offspring, which was always reckoned a blessedness, and was generally the happiness of virtuous women, when harlots were barren; and rejoice with the wife of thy youth; taken to be a wife in youth, and lived with ever since; do not despise her, nor divorce her, even in old age, but delight in her company now as ever; carry it not morosely and churlishly to her, but express a joy and pleasure in her; see Ecc 9:9. Jarchi interprets this of the law learned in youth; but it might be much better interpreted of the pure apostolic church of Christ, "the beulah", to whom her sons are married, Isa 62:4; to whom they should cleave with delight and pleasure, and not follow the antichristian harlot.