The eighth commandment is:
This commandment forbids false testimony, calumny, detraction, rash judgment, and lying.
This is to assert something contrary to the truth in a matter of justice (for example, under oath in a court of law) in order to harm someone – either by accusing an innocent person or by protecting the guilty.
This is to attribute to someone faults or defects that they do not have, or to exaggerate them, thereby unjustly damaging their reputation in the eyes of others.
This is to reveal, without necessity, the real faults or failings of a person to those who did not know them, thus unjustly diminishing their reputation and honor.
This is to think evil of another, to assume a moral fault on their part without sufficient reason, based only on suspicions or impressions.
This is to knowingly speak contrary to the truth, with the intention of deceiving the one who hears. Any statement that distorts the truth in order to mislead is a lie.
God, who is Truth itself, hates falsehood. Those who become accustomed to lying often suffer the consequences even in this life, before having to answer in the next for all their words.
One of the best-attested events in the history of the Church in Poland is what happened in the year 1070 to Saint Stanislaus, Bishop of Kraków.
At that time, Boleslaus, an impious and cruel prince, sat on the throne and persecuted the saint by every means in his power.
He incited against him the heirs of a certain Peter Milès, who had died three years earlier, leaving a piece of land to the Church. Confident of support, the heirs brought a lawsuit against the saint. All the witnesses, having been bribed or intimidated, failed to speak the truth, and the bishop was condemned to restore the disputed land.
Seeing that human justice had failed him, he boldly appealed to the justice of God and promised to produce as a witness the man who had lain in the tomb for three years.
His words were met with mockery and coarse laughter. But after three days of fasting and solemn prayer, the bishop went with all his clergy to the tomb of Peter Milès and ordered it to be opened. As expected, nothing was found but bones crumbling into dust. The laughter of unbelief rose on every side – when suddenly, at the command of the saint, spoken in the name of Him who is the Resurrection and the Life, the bones strengthened, came together, were clothed again with flesh – and before the astonished eyes of the entire people, the dead man appeared, taking the holy bishop by the hand.
He was led before Boleslaus and testified to the truth of the donation he had made.
Thus, the injustice that had seemed certain of victory was confounded. After giving his testimony, Saint Stanislaus asked him whether he preferred to return to the tomb or to live again for a few years.
The risen man replied:
“Because of my many sins, I am in Purgatory, where I suffer greatly. Yet I prefer to die again rather than remain in this miserable and perilous life.”
“But could you not do penance for your sins and thus avoid returning to the sufferings from which I have drawn you?”
“That is true,” he answered, “but I could also lose myself and be damned forever. I would much rather complete my punishment than return to life with the uncertainty of pleasing God and securing my salvation. The greatest grace you can grant me, O most holy Father, is to pray that the Lord may shorten my sufferings and receive me as soon as possible among the elect.”
“I will do so,” replied the bishop.
Then, accompanied by all his clergy, he led the dead man back in procession to the tomb. The man lay down in it at once, and immediately his body fell apart again into dust. It is believed that the saint soon obtained his deliverance.
This example is most remarkable, for it shows a soul from Purgatory, having experienced its sufferings, preferring that painful state to the uncertainty in which we live while still in this world.