Truthfulness
Allāh, the Exalted, said: (O you who have believed, fear Allāh and be with those who are truthful.) (The Noble Qur’ān 9:19)
Among the noble manners that the Prophet PBUH was famous for, even before prophet hood, is truthfulness and trust. In fact he PBUH was titled by the pagans of Makkah “The Truthful and Trust worthy”.
Truthfulness is a characteristic of the believers
Ibn Mas'ud RAA reported:
The Messenger of Allāh PBUH said: “Truth leads to piety and piety leads to Paradise - Jannah. A man persists in speaking the truth till he is recorded with Allāh as a truthful man. Lying leads to transgression and transgression leads to the Hell-fire. A man continues to speak falsehood till he is recorded with Allāh as a great liar.” (Al-Bukhāri and Muslim)
Hasan ibn Ali RAA said:
I remember (these words) from Messenger of Allāh PBUH: “Give up what is doubtful to you for that which is not doubtful; for truth is peace of mind and lying is doubt.” (At- Tirmidhi, declared sound by Al-Albani)
When revelation, through Jibreel, first came to the Prophet PBUH in the cave of Hira’a, he PBUH was terrified and he reached his house and said to his wife Khadija RAA: “O Khadija! What is wrong with me? I was afraid that something bad might happen to me.” Then he told her the story. Khadija said: “Nay! But receive the good tidings! By Allāh, Allāh will never disgrace you, for by Allāh, you keep good relations with your Kith and kin, speak the truth, help the poor and the destitute, entertain your guests generously and assist those who are stricken with calamities.” (Al-Bukhāri and Muslim)
Truthfulness should be in all of our daily practices
Hakim ibn Hizam RAA reported that:
Messenger of Allāh PBUH said: “Both parties in a business transaction have a right to cancel it so long as they have not separated; and if they tell the truth and make everything clear to each other (i.e., the seller and the buyer speak the truth, the seller with regard to what is purchased, and the buyer with regard to the money) they will be blessed in their transaction, but if they conceal anything and lie, the blessing on their transaction will be eliminated.” (Al-Bukhāri and Muslim)
Narrated Abdullah ibn Aamir RAA:
My mother called me one day when Messenger of Allāh PBUH was sitting in our house. She said: Come here and I shall give you something. The Messenger of Allāh PBUH asked her: What did you intend to give him? She replied: I intended to give him some dates. The Messenger of Allāh PBUH said: If you were not to give him anything, a lie would be recorded against you. (Abu Dawood, declared sound by Al-Albani)
So be aware, even lying to the children is not justifiable.
The greatest of all truthfulness is to be truthful with Allāh SWT
When the heart attends that Allāh SWT is the All-Knowing, who knows what even the heart conceals, certainly this is a genuine propeller in pursuing truthfulness with Allāh SWT.
Allāh SWT praised those who are truthful with Him. On the day of judgment Allāh SWT will say: (This is the Day when the truthful ones will benefit from their truthfulness. For them are gardens [in Paradise] beneath which rivers flow, wherein they will abide forever, Allāh being pleased with them, and they with Him. That is the great attainment.) (The Noble Qur’ān 5:119)
Lying is a characteristic of the hypocrites
Abdullah ibn Amr bin Al-'Aas RAA said:
The Messenger of Allāh PBUH said: “Whosoever possesses these four characteristics is a pure hypocrite; and anyone who possesses one of them possesses a characteristic of hypocrisy till he gives it up. These are: when he is entrusted with something, he proves dishonest; when he speaks, he tells a lie; when he makes a covenant, he proves treacherous; and when he quarrels, he behaves in very imprudent, evil, insulting manner.” (Al-Bukhāri and Muslim)