en_tn/gen/27/12.md

I will seem to him as a deceiver

"he will think that I am a liar" or "he will know that I am deceiving him"

I will bring a curse upon me and not a blessing

Being cursed or blessed is spoken of as if a curse and a blessing are objects that are placed on a person. Alternate translation: "Then because of this, he will curse me and not bless me" (See: rc://en/ta/man/translate/figs-metaphor)