Hadith: There are three (types of people) to whom Allah will not speak (on the Day of Judgment), nor will He purify, and they will incur a painful punishment: an aged person who commits adultery, a poor person who is arrogant, and a man who has made (swearing by) Allah as his goods; as he does not buy or sell without swearing by Allah

عن سلمان الفارسي رضي الله عنه أن رسول الله صلى الله عليه وسلم قال: «ثلاثة لا يُكَلِّمُهم الله، ولا يزكيهم، ولهم عذاب أليم: أُشَيْمِط زَانٍ، وعائل مُسْتَكْبِر، ورجل جعل الله بضاعته: لا يشتري إلا بيمينه، ولا يبيع إلا بيمينه».
[صحيح] - [رواه الطبراني]

Salmān al-Fārisi (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "There are three (types of people) to whom Allah will not speak (on the Day of Judgment), nor will He purify, and they will incur a painful punishment: an aged person who commits fornication, a poor person who is arrogant, and a man who has made (swearing by) Allah as his goods; as he does not buy or sell without swearing by Allah.”
[Authentic hadith] - [At-Tabaraani]

Explanation

The Prophet (may Allah's peace and blessings be upon him) informs us about three types of sinners who will receive the severest punishment because of the hideousness of their crimes. One of them is the elderly person who commits fornication, because the urge to commit that sin is weak given his old age. This shows that the reason he is committing fornication is his love of sin and vice. Although fornication is despised regardless of who commits it, it is even more despised in old age. The second is a poor person who treats people with arrogance. Although arrogance is a despicable trait regardless of who displays it, the poor person has no wealth that prompts him to be arrogant, so his arrogance along with the absence of a motive for it proves that arrogance is in his nature. The third is the person who makes swearing by Allah his habit and uses it frequently when selling and buying, thus being disrespectful to the name of Allah and using it as a means to earn money.