'Deceitfully' in the Bible

“Their tongue is a murderous arrow;It speaks deceit;With his mouth one speaks peace to his neighbor,But in his heart he lays traps and waits in ambush for him.

You, O Lord are [uncompromisingly] righteous and consistently just when I plead my case with You;Yet let me discuss issues of justice with You:Why has the way of the wicked prospered?Why are those who deal in treachery (deceit) at ease and thriving?

that you have deceived yourselves; for you sent me to the Lord your God, saying, “Pray for us to the Lord our God; and whatever the Lord our God says, declare it to us and we will do it.”

“Cursed is the one who does the work of the Lord negligently,And cursed is the one who restrains his sword from blood [in executing the judgment of the Lord].