A double minded man [is] unstable in all his ways.
Their heart is divided; now shall they be found faulty: he shall break down their altars, he shall spoil their images.
But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed.
They speak vanity every one with his neighbour: [with] flattering lips [and] with a double heart do they speak.
1 Chronicles 12:33
Of Zebulun, such as went forth to battle, expert in war, with all instruments of war, fifty thousand, which could keep rank: [they were] not of double heart.
Happy [is] the man that feareth alway: but he that hardeneth his heart shall fall into mischief.
Wherefore it shall come to pass, [that] when the Lord hath performed his whole work upon mount Zion and on Jerusalem, I will punish the fruit of the stout heart of the king of Assyria, and the glory of his high looks.
Hearken unto me, ye stouthearted, that [are] far from righteousness:
And all the people shall know, [even] Ephraim and the inhabitant of Samaria, that say in the pride and stoutness of heart,