Parshat Ki Teitzei is packed with commandments, a great deal of commandments. However, this time, we will only address a small portion of them, ones with significant ethical implications.
First and foremost, the importance of speech. The Torah teaches:
"When you make a vow to Adoani, your God, do not be slow to fulfill it. For Adonai, your God will surely demand it of you, and you will be guilty of sin."
In other words, a person is required to uphold their speech. Speech is indeed a serious matter. On one hand, it can be said that speech is the easiest thing for a person to do! There is hardly any effort necessary to utter words from our mouths. Yet speech, as an essential aspect of human nature, becomes so serious that the Torah even warns that failing to fulfill a vow is a sin.
So, alternatively, perhaps it is better not to make vows at all? To this, the Torah responds - yes, it is preferable. "But if you refrain from making a vow, you will not be guilty. Whatever your lips utter you must be sure to do, because you made your vow freely to Adonai your God with your own mouth." This means that if you do choose to make a vow to God, then you must stand by what you say, even though God is also willing for you not to make the vow.
Immediately following, the text moves on to something else also related to the mouth. Our mouth serves two purposes - to speak and to eat. You need to uphold your speech, but you also need to take care of the food-related aspects of those who work for you.
It is written: "When you enter your neighbor’s vineyard, you may eat your fill of grapes, but do not put any in your basket." In other words, the owner of the vineyard who employs someone cannot prevent the worker from eating grapes. This would constitute an element of cruelty. It would be wrong if a person cares for the sustenance of others in cultivating their vineyard, while preventing his workers from engaging in their own sustenance,
However, reversely, it is also forbidden for the worker to cynically exploit this. Regarding the worker, it is said: "But you must not put any in your vessel." In other words, you must not take these grapes home. The same principle applies to- "When you enter your neighbor’s standing grain, you may pluck the ears with your hand, but do not put a sickle to your neighbor’s standing grain." This means that during your work, you may make use of the owner's resources, but do not turn yourself into a thief.
So, we have a complete integration here where the Torah speaks about the sanctity of what comes out of your mouth but it also addresses the employer's responsibility for what goes into the mouth of his workers.