Everyone who thirsts, come to the waters, and he who has no money, come, buy, and eat! And come, buy wine and milk without money and without price. Isa 55:1

Also in Jeremiah 13:1, 2, 11.

The kingdom of heaven is like treasure hidden in a field, which a man (homo) finds and hides, and in his joy he goes and sells whatever he has and buys that field. Again, the kingdom of heaven is like a trader seeking fine pearls, who, having found one pearl of great price, went and sold all that he had and bought it. Matt 13:44-46.

And in the same gospel,

The wise virgins said to the foolish ones, Go to those who sell and buy oil for yourselves. While they were going to buy, the Bridegroom came. Matt 25:9, 10.

[2] Because 'buying' meant a making one s own, a clear distinction is made in the Word between things bought with silver and those acquired in some other way. Slaves bought with silver were so to speak the buyer's own, and were like 'those born in the house, but in a lower degree. This also explains why the two are mentioned together in various places, as in the command in Gen 17:3, 'He who is born in your house and he who is bought with your silver must be circumcised', or as in Lev 22:11, 'If a priest buys a person^a - a buying with silver - [this person] and one who is born in his house shall eat of his bread'. From this one may see what is meant in the Word by 'the redeemed of Jehovah',^b namely those who have acquired good and truth, thus those to whom things that are the Lord's have been made over as their own.

Notes