GEN1235 Rabbeinu Yonah, in his Sha’arei Teshuvah, classified the various manifestations of deceit and falsehood, in nine separate categories. … The third category is … An individual whose deceitfulness will not cause his neighbor actual financial loss, but will prevent him from receiving a benefit or financial gain, while directing that gain, instead, towards himself. Or, perhaps he craftily persuades his neighbor to give him a gift because of his artfully feigned friendship. While this individuals did not actually cause his neighbor financial loss, he, too, is a man of deceit, and he will be punished accordingly. The Sages said, Sanhedrin 92a “He who is deceitful with his word, is as though he had worshiped idolatry.” As Yaakov said when his other suggested that he pose as Esau to obtain the Berachos from his father, Yitzchak [this verse], Perhaps my father will touch me, and I will be in his eyes as a deceiver. And elsewhere, we find the word תעתעים used in regard to idolatry, as it says Jeremiah 10:15, They are vanity, the work of deception. Sha’arei Teshuvah, 3:180 FENDEL 109-10