A. Iniquity (al-Baghi) is to desire exaltation without right.
Al-Munawi

Iniquity is seeking to exceed the limits demarcating moderation in what is sought.
Al-Raghib

A.2. Texts from the Qur’an and the Sunnah Concerning Iniquity

Wicked is what they have sold their souls for, disbelieving in what Allah has revealed, because of their iniquity that Allah would send revelation, from His bounty, unto whomsoever He wills of His servants…
Qur’an 2:90

The religion with Allah is faith and obedience (Islam). The people given the scripture did not differ except after knowledge came to them seeking worldly advantage (baghyan) between themselves. Whoever rejects the signs of Allah, Allah is swift in reckoning.
Qur’an 3:19

Say! Rather, my Lord has forbidden indecencies, both manifest and hidden, sin, iniquity, that you join as partners with Allah wherein He has revealed no authority, and that you speak against Allah wherein you have no knowledge.
Qur’an 7:33

O You people! Surely, your iniquity is but against yourselves.
Qur’an 10:23

The Prophet, peace upon him, was asked, “O Messenger of Allah! Which people are best?” He responded, “Every one [possessing] a Makhmum heart, a truthful tongue.” They said, “We know of the truthful tongue. What is the Makhmum heart?” He said, “It is god-conscious, pure, contains no sin, harbors no iniquity, nor rancor, or envy.”
Ibn Majah, #4216

The Prophet, peace upon him, said, “There is no sin whose perpetrator is more deserving to have the punishment hastened for him than iniquity and breaking blood ties.”
Tirmidhi, #2511

The Prophet, peace upon him, mentioned, “The worst form of usury is iniquity against the honor of a Muslim.”
Abu Dawud, 4876

A.3. Sayings of the Scholars Concerning Iniquity (Baghi)

If one mountain were to commit iniquity again another, Allah would crush the transgressor.
Ibn ‘Abbas, Dhamm al-Baghi

Sa’id bin Jubayr said concerning the verse, They neither desire exaltation in the earth nor corruption therein… (Qur’an 28:73) “That is to say iniquity (Baghi).”
Sa’id bin Jubayr, Dhamm al-Baghi

O My sons! You should know that the quickest sin to be punished is iniquity. The vilest ally is aggression. The worst character trait is stinginess. And the most wicked etiquette is excessive condemnation.
Safiyy bin Rabah al-Tamimi