Musar על תענית 14:7

The Sages also stated: "if one steals from his fellow even the worth of a peruta (small coin), it is as if he takes his life from him" (Bava Kama 119a). This teaching reveals to us, the graveness of this sin even for a small amount. They further said: "the rains are withheld only because of the sin of theft" (Taanit 7b). And "for a basketful of sins, which sin prosecutes at the head of all of them? - theft" (Vayikra Raba 33:3). And "the generation of the flood had their fate sealed only because of the sin of theft" (Sanhedrin 108a).