No need of spoil - Better, no lack of gain, lack of honest gain.

The heart of her husband -
3. She is an unspotted wife. The heart of her husband doth safely trust in her - he knows she will take care that a proper provision is made for his household, and will not waste any thing. He has no need for spoil - he is not obliged to go out on predatory excursions, to provide for his family, at the expense of the neighboring tribes.

The heart of her husband doth safely trust in her, so that he shall have no need of (h) spoil.
(h) He will not need to use any unlawful means to gain his living.

The heart of her husband doth safely trust in her,.... Christ her Maker is her husband, who has asked her in marriage, and has betrothed her to himself in righteousness; and of whose chaste love, and inviolable attachment to him, he is fully satisfied, as well as of her fidelity in keeping what he commits unto her; he trusts her with his Gospel and ordinances, which she faithfully retains and observes; and with his children born in her, who are nursed up at her side, to whom she gives the breasts of ordinances, bears them on her sides, and dandles them on her knees, as a tender and careful mother does, Isaiah 60:4;
so that he shall have no need of spoil; he shall never want any; by means of the word preached in her, prey and spoil shall be taken out of the hands of the mighty, and he shall divide the spoil with them; or have souls snatched out of the hands of Satan, and translated into his kingdom, Isaiah 53:12. The Septuagint version understands it of the virtuous woman, and not of her husband; "such an one as she shall not want good spoils"; now, prey or spoil sometimes signifies food, as in Psalm 111:5; and so Jarchi interprets it here; and then the sense is, she shall not want spiritual provisions; she shall have plenty of them from her husband, who reposes such confidence in her; or shall not want excellent treasures, as the Arabic version, which also understands it of her; such are the word and ordinances, and particularly precious promises, which are more rejoicing than a great spoil, Psalm 119:162; and so Ambrose interprets (y) it of the church, who needs no spoils because she abounds with them, even with the spoils of the world, and of the devil.
(y) Enarrat. in loc. p. 1099. tom. 2.

heart . . . trust in her--He relies on her prudence and skill.
no need of spoil--does not lack profit or gain, especially, that obtained by the risk of war.

The reason for this is now given:
11 ב The heart of her husband doth trust her,
And he shall not fail of grain.
If we interpret שׁלל, after Ecclesiastes 9:8, as subject, then we miss לּו; it will thus be object., and the husband subj. to לא יחסּר: nec lucro carebit, as e.g., Fleischer translates it, with the remark that שׁלל denotes properly the spoil which one takes from an enemy, but then also, like the Arab. ḍanymat, can mean profit and gain of all kinds (cf. Rdiger in Gesenius' Thes.). Thus also in our "kriegen" = to come into possession, the reference to war disappears. Hitzig understands by שׁלל, the continual prosperity of the man on account of his fortunate possession of such a wife; but in that case the poet should have said שׂמחת שׁלל; for שׁלל is gain, not the feeling that is therewith connected. There is here meant the gain, profit, which the housewife is the means of bringing in (cf. Psalm 78:13). The heart of her husband (בּעלּהּ) can be at rest, it can rest on her whom it loves - he goes after his calling, perhaps a calling which, though weighty and honourable, brings in little or nothing; but the wife keeps the family possessions scrupulously together, and increases them by her laborious and prudent management, so that there is not wanting to him gain, which he properly did not acquire, but which the confidence he is justified in reposing in his wife alone brings to him. She is to him a perpetual spring of nothing but good.

No need - He shall have no need to use indirect courses to get wealth.