Prohibiting Oaths by Other Than Allah

Also, in his letter, he says: We observe, O honorable Shaykh, that some people, specifically school students, swear by their success, saying: "By my success," or "By my good fortune." Is this shirk (associating partners with Allah)? Please guide us with the correct direction to eliminate this habit, knowing that it is widespread among many students. May Allah guide you?
Answer: Swearing by other than Allah is among the major sins and among the forbidden acts of shirk (associating partners with Allah). The Prophet (peace and blessings be upon him) clarified this. Initially, people used to swear by their fathers; the Arabs used to swear by their fathers and mothers. The Prophet (peace and blessings be upon him) then disapproved of that. He found some of the Companions in their company swearing by their fathers, so he forbade them and said: "Indeed, Allah has forbidden you to swear by your fathers." He said: "Whoever is swearing, let him swear by Allah or remain silent." He said: "Do not swear by your fathers, nor by your mothers, nor by idols, and do not swear by Allah except when you are truthful." He (peace and blessings be upon him) said: "Whoever swears by other than Allah has committed kufr (disbelief) or shirk (associating partners with Allah)." He said: "Whoever swears by the trust is not one of us." When Sa'd said: "O Messenger of Allah! I swore and said in my oath: By al-Lat and al-'Uzza," he told him: "Say: (La ilaha illa Allah) [There is no deity but Allah]... seven times." In some narrations: "Seek refuge in Allah from Satan."
The point is that swearing by other than Allah is a major sin and among the forbidden acts of shirk (associating partners with Allah). It is not permissible to swear by one's success, nor by one's father, nor by one's mother, nor by the life of so-and-so, nor by the head of so-and-so, nor by the Prophet, nor by the Ka'bah, nor by the honor of so-and-so. All of these are major sins and forbidden acts of shirk (associating partners with Allah), and no one should ever engage in them. If someone does any of this, he must hasten to repent from the forbidden acts of shirk (associating partners with Allah) and from minor shirk. It may be major shirk if he holds in his heart the exaltation of the thing by which he swears, and that he exalts it as he exalts Allah, or if he believes in it something of worship or secrecy. This would be major shirk, may Allah keep us safe from it. But if it slips from his tongue without intention, but as a habit, then this is minor shirk. One should be cautious of this, and not swear by his father, nor by his mother, nor by his success, nor by his good fortune, nor by anything else. However, if he said: "By my good fortune," meaning: "By Allah's good fortune for me," and his intention is by Allah's good fortune, that is another matter. I will succeed by Allah's good fortune, or something like that. But "by my good fortune" intending "by my good fortune" as an oath by it, this is not permissible; rather, it is among the forbidden acts of shirk (associating partners with Allah).
So the conclusion is that it is obligatory for the Muslim to be cautious of the pitfalls of the tongue, for the pitfalls of the tongue are numerous and serious, and this is one of them. Swearing by other than Allah is among the pitfalls of the tongue and among the defects of the tongue. So let him be extremely cautious of that. And if he sees someone doing it, he should disapprove of it, teach him, advise him, and say to him: This is not permissible, and that it is obligatory to swear by Allah alone, (Glorified and Exalted is He). Yes.