The comparison points to the enlarged commerce of the Israelites consequent on their contact with the Phoenicians under David and Solomon; compare Proverbs 31:24.

She is like the merchants' ships -
3. She acts like merchants. If she buy any thing for her household, she sells sufficient of her own manufactures to pay for it; if she imports, she exports: and she sends articles of her own manufacturing or produce to distant countries; she traffics with the neighboring tribes.

She is like the merchant ships,.... Not like a single one, but like a navy of them, that cross the seas, go to foreign parts, and come back laden with rich goods: so the church of Christ, and her true members, like ships of burden, trade to heaven, by prayer and other religious exercises, and return with the riches of grace and mercy, to help them in time of need; and though they have often difficult and dangerous passages, are tossed with tempests, and covered with billows; yet, Christ being their pilot, faith their sail, and hope their anchor, they weather the seas, ride out all storms, and come safe home with their merchandise;
she bringeth her food from afar: from a far country, from Egypt particularly, from whence corn for bread, as the word here used signifies, was fetched and carried in ships to divers parts of the world (p); to which the allusion may be: in a spiritual sense, it may mean that the church brings her food or bread from heaven, the good land afar off; where God her father, Christ her husband, and her friends the angels are; with whom she carries on a correspondence, and from hence she has her food for her family; not from below, on earth; not dust, the serpent's food; nor ashes, on which a deceitful heart feeds; nor husks, which swine eat; but the corn of heaven, angels' food, the hidden and heavenly manna; the bread of life, which comes down from heaven; the Gospel of the grace of God, the good news from a far country.
(p) Bacchylides spud Athenaei Deipnosoph. l. 2. c. 3. p. 39.

The following proverb praises the extent of her housewifely transactions:
14 ה She is like the ships of the merchant -
Bringeth her food from afar.
She is (lxx ἐγένετο) like merchant ships (כּאניות, indeterminate, and thus to be read kōǒnı̂joth), i.e., she has the art of such ships as sail away and bring wares from a distance, are equipped, sent out, and managed by an enterprising spirit; so the prudent, calculating look of the brave wife, directed towards the care and the advancement of her house, goes out beyond the nearest circle; she descries also distant opportunities of advantageous purchase and profitable exchange, and brings in from a distance what is necessary for the supply of her house, or, mediately, what yields this supply (ממּרחק, Cod. Jaman. ממרחק, cf. under Isaiah 10:6), for she finds that source of gain she has espied.

From afar - By the sale of her home - spun commodities she purchases the choicest goods which come from far countries.