Abu Dawud

Benefits and Issues:
Truth and falsehood (sidq wa kidhb) are not limited only to the words of the tongue; rather, their scope extends to actions and intentions as well.
From an intellectual perspective, if a person is a seeker of truth and acts according to it, and avoids its opposite, then this is a great virtue.
Otherwise, sooner or later, he will not be able to escape disgrace.

Hadith Commentary:
That is why it is said, "Innamal a‘malu bikhawatimiha" — the value of deeds is based on their conclusion (i.e., the final state).
May Allah, the Most Pure, grant every Muslim, every reader of Sahih al-Bukhari, and this insignificant, sinful servant a good ending (khatimah bil-khayr), so that our end is upon tawhid, the Sunnah, and the pure testimony of faith (kalimah tayyibah).
It is hoped that at this point all esteemed readers will say Ameen. Ameen.
O Lord of the worlds!

Hadith Commentary:
(1)
A person, by speaking the truth continuously, becomes accustomed to truthfulness and acquires mastery over it, to the extent that he attains the rank of "sidq" (truthfulness), which is the level just below prophethood. On the other hand, a person who becomes accustomed to lying is written as a liar (kadhdhab) in the sight of Allah, and the notion of his being a liar is cast upon all of creation.

(2)
Among the teachings upon which the Messenger of Allah (sallallahu alayhi wa sallam) based his call was the adoption of truthfulness. Thus, Abu Sufyan (radi Allahu anhu) admitted to this in the court of Heraclius (see: Sahih al-Bukhari, Book of Revelation, Hadith: 7).
Furthermore, the Prophet (sallallahu alayhi wa sallam) said:
"Faith and disbelief, truth and falsehood, and trustworthiness and betrayal cannot be combined in the heart of a Muslim."
(Musnad Ahmad: 2/349)

Hadith Commentary:
Vocabulary of the Hadith:
The original meaning of "birr" in the Arabic language is to fulfill someone’s right completely, whether it pertains to the rights of Allah or the rights of the servants. In contrast, "fujur" refers to deviating from the path and abandoning steadfastness.

Hadith Commentary:
Vocabulary of the Hadith:
Siddiq (Truthful):
One whose words and actions, tongue and heart, are in agreement,
because truthfulness (sidq) is when speech conforms to the heart and to reality. Whoever adopts truthfulness,
he is deemed a siddiq (truthful one) in the sight of Allah and will receive its reward, and he will also be regarded as truthful among people.
On the contrary, whoever makes lying a habit,
he is deemed a liar in the sight of Allah and will be deserving of its punishment and retribution, and he will also be known and recognized as a liar among people.

Benefits and Issues:
From this hadith, it is understood that
speaking the truth is, in itself, a good and praiseworthy habit,
whose special quality and distinction is that it makes a person righteous and virtuous in all aspects of life and makes him deserving of Paradise,
because "birr" (righteousness) is the collective name for all good deeds, and a person who always speaks the truth attains the rank of siddiqiyyah (absolute truthfulness).
On the contrary, lying is, in itself, a vile and evil trait,
whose characteristic is that
it creates a tendency and inclination towards immorality, wickedness, and evil within a person,
turning his entire life into a life of sin and leading him to Hellfire, and one who becomes accustomed to lying,
reaches the level of extreme falsehood (kadhdhabiyyah) and becomes deserving of Allah’s curse.

Explanation:
1:
It is understood that one should always avoid lying and adopt truthfulness, because the consequence of lying is Hell and the consequence of truthfulness is Paradise.

Takhrij:
«أخرجه البخاري، الأدب، باب قول الله تعالي: "يأيها الذين آمنوا اتقوا الله"، حديث:6094، ومسلم، البر والصلة، باب قبح الكذب...، حديث:2607.»©Explanation:
In this hadith, there is an indication towards the good end (husn al-khatimah) of the one who speaks the truth, and that he is safe and protected from a bad outcome.