That defines honesty and half-truth. Can't find it with a search - I'm missing the right keywords.

This may not be what you are looking for, but they are about lying:

D&C 50:17-18
17 Verily I say unto you, he that is ordained of me and sent forth to preach the word of truth by the Comforter, in the Spirit of truth, doth he preach it by the Spirit of truth or some other way?
18 And if it be by some other way it is not of God.

D&C 93:24-26
24 And truth is knowledge of things as they are, and as they were, and as they are to come;
25 And whatsoever is more or less than this is the spirit of that wicked one who was a liar from the beginning.
26 The spirit of truth is of God…

D&C 63:17
17 Wherefore, I, the Lord, have said that the fearful, and the unbelieving, and all liars, and whosoever loveth and maketh a lie, and the whoremonger, and the sorcerer, shall have their part in that lake which burneth with fire and brimstone, which is the second death.

D&C 129:7
7 ...it is contrary to the order of heaven for a just man to deceive;...

2 Nephi 9:34
34 Wo unto the liar, for he shall be thrust down to hell.

2 Nephi 28:8-11
And there shall also be many which shall say: Eat, drink, and be merry; nevertheless, fear God--he will justify in committing a little sin; yea, lie a little ...; there is no harm in this; and do all these things, for tomorrow we die; and if it so be that we are guilty, God will beat us with a few stripes, and at last we shall be saved in the kingdom of God.
9 Yea, and there shall be many which shall teach after this manner, false and vain and foolish doctrines, and shall be puffed up in their hearts, and shall seek deep to hide their counsels from the Lord; and their works shall be in the dark. ...
11 Yea, they have all gone out of the way; they have become corrupted.

Jeremiah 48:10
Cursed be he that doeth the work of the LORD deceitfully...


Mormon writer Robert J. Matthews says, in the October 1994 Ensign article entitled "Thou Shalt Not Bear False Witness," that the ninth commandment is a

"strong declaration against ... gross understatements, fabrication, or the willful giving of any explanation not supported by the facts.... Even sharing the truth can have the effect of lying when we tell only half-truths that do not give the full picture. We can also be guilty of bearing false witness and lying if we say nothing, particularly if we allow another to reach a wrong conclusion while we hold back information that would have led to a more accurate perception. In this case it is as though an actual lie were uttered.... Lying and misrepresentation in all of their forms are wrong, no matter how they may be rationalized, and those who silently let these evils pass unchallenged are also doing wrong".

Marvin J. Ashton made the following comments in his sermon "This Is No Harm" (from Ensign magazine 2000):

"A lie is any communication given to another with the intent to deceive." A lie can be effectively communicated without words ever being spoken. Sometimes a nod of the head or silence can deceive....

It is a tragedy to be the victim of lies. Being trapped in the snares of dishonesty and misrepresentation does not happen instantaneously. One little lie or dishonest act leads to another until the perpetrator is caught in the web of deceit. ...

A wise person will not allow himself to be victimized by the unscrupulous because of false pride. Oftentimes people are swindled because false pride prevents them from asking questions and seeking additional information. For fear of embarrassment or being thought ignorant, a prospect ofttimes nods his head in the affirmative when he really doesn't understand the glib salesman's line of chatter. "What does that mean?" "What are the risks?" "What are the pitfalls?" "What is the history of the company?" "What references do you have?" are questions worthy of pursuit. ....If prudent decisions cannot be reached on the basis of one's own expertise, advice should be sought from knowledgeable and trusted counselors. Offers that cannot wait or stand review are not worthy.

[My comment: Although Ashton is referring here to unscrupulous salesmen and promoters of business schemes, the advice would also be excellent for those who are investigating Mormonism, and listening to the deceptive pitch and pressure of the Mormon missionaries.]

If Only...