Deuteronomy 6:10

And when the Lord thy God hath brought thee into the land which he promised to Abraham, Izhak, and Jakob, thy fathers, to give thee cities great and goodly which thou didst not toil in building,

AND IT SHALL BE, WHEN THE ETERNAL THY G-D SHALL BRING THEE etc. He mentions here that, with the increase of beneficence, Israel [i.e., each individual Israelite] should remember the days of his affliction and of his anguish, when he was a servant in Egypt, and he is not to forget the G-d Who brought him forth out of that bondage to this goodness. Instead he is always to remember His mercies and fear Him and serve Him as a servant does his master. And in the opinion of our Rabbis the verse further alludes [to the law] that anything found in the houses full of all ‘good’ things [that were occupied in the conquest of Canaan] may be used, even if they contained things forbidden by the Torah such as kadli of swine,” which Rashi interprets to mean “dried swine.” See Numbers 31:23 — Vol. IV, p. 367. of swine, or the produce of a vineyard sown with diverse seeds, or fruits of the first three years of a tree., 19:23. Even regarding cisterns, it is possible that in their construction forbidden materials were used in their coat of pitch [such as forbidden wine; hence Scripture mentioned and cisterns hewn out, which thou didst not hew to indicate that they, too, were permitted to them]. Or it may be that the cisterns are mentioned figuratively, to denote the abundance of good things, thus giving them mastery over all that was found in the Land both permissible and impermissible. Thus all forbidden articles were permitted to them except [for those that were forbidden as a result of] the prohibition of idols, as he will yet clarify, thou shalt not covet the silver or the gold that is on them, nor take it unto thee etc. Therefore, he mentions here in the next section, ye shall break down their altars,, Verse 5. to destroy the idols and their appurtenances. But whatever else was found in the Land was permissible. This permission lasted until they consumed the spoil of their enemies., 20:14: and thou shalt eat the spoil of thine enemies. And some Rabbis say that this permission applied [only] to the seven years of [the] conquest [of the Land], and so it appears in the Gemara, in the first chapter of Tractate Chullin. Now the Rabbi [Moshe ben Maimon] wrote in the Laws of the Kings and their Wars: “Armed soldiers, when they enter the border of the nations and loot from them, are permitted to eat n’veiloth and treifoth the flesh of swine and the like if they are hungry and do not find …

.אשר לא בנית ובתים מלאים כל טוב אשר לא מלאתYou will attain wealth without having toiled for it.