The Prophet (ﷺ) said: Do not swear by your fathers, or by your mothers, or by rivals to Allah; and swear by Allah only, and swear by Allah only when you are speaking the truth.
Hadith Text & Reference
The Prophet (ﷺ) said: "Do not swear by your fathers, or by your mothers, or by rivals to Allah; and swear by Allah only, and swear by Allah only when you are speaking the truth."
Source: Sunan Abi Dawud 3248 | Book: Oaths and Vows (Kitab Al-Aiman Wa Al-Nudhur)
Prohibition of Swearing by Created Beings
The prohibition against swearing by fathers and mothers establishes that oaths should only be taken by Allah's name. Swearing by created beings implies giving them the sanctity reserved for the Creator, which constitutes shirk (associating partners with Allah).
The phrase "rivals to Allah" (al-ālihah) refers to any object of worship besides Allah, including idols, saints, or any created entity. Such oaths are invalid and forbidden as they attribute divine qualities to creation.
Exclusive Sanctity of Allah's Name
The command "swear by Allah only" emphasizes tawhid (monotheism) in speech and worship. An oath (yamin) is a solemn declaration that invokes Allah's name as witness, making it a form of worship that must be directed solely to Him.
Scholars explain that swearing by other than Allah is prohibited whether intended as an actual oath or mere emphasis in speech, as it diminishes the unique majesty of Allah's name.
Condition of Truthfulness in Oaths
The final instruction "swear by Allah only when you are speaking the truth" establishes two crucial principles: the obligation of truthfulness in oaths, and the gravity of false oaths which constitute major sins.
Imam Nawawi comments that this teaches Muslims to reserve oaths for necessary matters of importance, and to ensure complete honesty when invoking Allah's name, as false oaths violate Allah's sanctity and damage social trust.
Legal Implications & Expiation
If someone mistakenly swears by other than Allah, they should say "Lā ilāha illā Allāh" and not fulfill such an oath. A valid oath must be sworn by Allah's names or attributes.
Breaking a valid oath requires kaffarah (expiation) as detailed in Quran 5:89: feeding ten poor persons, clothing them, or freeing a slave. If unable, fasting three days consecutively.