Every valley shall be filled, and every mountain and hill shall be brought low; and the crooked shall be made straight, and the rough ways shall be made smooth;

The voice of him that crieth in the wilderness, Prepare ye the way of the LORD, make straight in the desert a highway for our God.

I will go before thee, and make the crooked places straight: I will break in pieces the gates of brass, and cut in sunder the bars of iron:

For they that are such serve not our Lord Jesus Christ, but their own belly; and by good words and fair speeches deceive the hearts of the simple.

Every valley shall be exalted, and every mountain and hill shall be made low: and the crooked shall be made straight, and the rough places plain:

Burning lips and a wicked heart are like a potsherd covered with silver dross. He that hateth dissembleth with his lips, and layeth up deceit within him; When he speaketh fair, believe him not: for there are seven abominations in his heart.read more.
Whose hatred is covered by deceit, his wickedness shall be shewed before the whole congregation.

And Jacob said to Rebekah his mother, Behold, Esau my brother is a hairy man, and I am a smooth man:

And she put the skins of the kids of the goats upon his hands, and upon the smooth of his neck:

The words of his mouth were smoother than butter, but war was in his heart: his words were softer than oil, yet were they drawn swords.

The way of the just is uprightness: thou, most upright, dost weigh the path of the just.