Vayikra 14:34

ונתתי נגע צרעת [WHEN YOU COME TO THE LAND …]I WILL PUT THE PLAGUE OF THE LEPROSY — This was an announcement to them that these plagues would come upon them (Sifra, Metzora, Section 5 4; Horayot 10a), because the Amorites concealed treasures of gold in the walls of their houses during the whole 40 years the Israelites were in the wilderness (in order that these might not possess them when they conquered Palestine,) and in consequence of the plague they would pull down the house and discover them (Leviticus Rabbah 17:6).

כִּ֤י תָבֹ֙אוּ֙ אֶל־אֶ֣רֶץ כְּנַ֔עַן אֲשֶׁ֥ר אֲנִ֛י נֹתֵ֥ן לָכֶ֖ם לַאֲחֻזָּ֑ה וְנָתַתִּי֙ נֶ֣גַע צָרַ֔עַת בְּבֵ֖ית אֶ֥רֶץ אֲחֻזַּתְכֶֽם׃

When you come into the land of Kena῾an, which I give to you for a possession, and I put the plague of żara῾at in a house of the land of your possession;