Among the greatest major sins are disobedience to parents and the false oath (al-yamin al-ghamus)

It is narrated from Sayyiduna Abdullah bin Unays al-Juhani (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The greatest of the major sins are: associating partners with Allah, disobedience to parents, and 'al-yamin al-ghamus' (the ruinous false oath). And when a person swears a false oath by Allah and inserts into it (something untrue) even as much as the wing of a mosquito, Allah Almighty will make it a black spot in his heart on the Day of Resurrection."
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.

Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) says: We used to count 'al-yamin al-ghamus' among the sins for which there is no expiation (that is, it is not forgiven without repentance). It was asked: What is 'al-yamin al-ghamus'? He said: That a man seizes the wealth of another by means of his (false) oath.
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it; however, this statement of the Companion has been accepted with this chain.

It is narrated from Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever, standing at this pulpit of mine, swears a sinful (false) oath, let him take his seat in Hell - or he said: Hell becomes obligatory for him - even if it is over a green miswak of the pilu tree."
This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Jabir bin Abdullah al-Salami (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever swears a sinful oath at this pulpit of mine, let him take his seat in the Fire."

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "No male slave or female slave swears a sinful oath at this pulpit, even over a single fresh miswak, except that Hell becomes obligatory for them."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), because its narrator al-Hasan bin Yazid (Abu Yunus) is strong and a devout worshipper, but the two Shaykhs did not record it.