Q: Is it permissible to swear by the Prophet (peace be upon him)?
A: It is not permissible to swear by any creature, including the Prophet (peace be upon him), the Ka`bah, the trust, or anything else according to the majority of scholars. Rather, some scholars reporteda consensus that this is prohibited. An odd view, however, is reported about the permissibility of swearing by the Prophet (peace be upon him), which is a groundless opinion. In fact, it is an invalid view that contradicts the preceding consensus of scholars and Hadith Sahih (authentic) mentioned on this issue.
Among these Hadith is the onerelated by AlBukhari and Mulimfrom Amir AlMu'minin (Commander of the Believers), `Umar ibn AlKhattab (may Allah be pleased with him), that the Prophet (peace be upon him) said: Verily! Allah forbids you to swear by your fathers. If one has to take an oath, they should swear by Allah or else keep silent.
It is also related in the Two Sahih Books of Hadith (i.e. AlBukhari and Muslim)on the authority of Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace be upon him) said: Whoever swears, saying (by error) in their oath 'By AlLat and Al`Uzza,' they should say, 'There is no deity but Allah.'
Moreover, AlTirmidhy and AlHakim related through a sound Sanad (chain of narrators)from Ibn `Umar (may Allah be pleased with them both) that the Prophet (peace be upon him) said: Anyone who swears by other than Allah has become a Kafir (disbeliever) or Mushrik (one who associates others with Allah in His Divinity or worship).
Abu Dawud relatedfrom Buraydah ibn AlKhasib (may Allah be pleased with him) that the Prophet (peace be upon him) said: Anyone who swears by Amanah (trust) is not one of us.
On the authority of Abu Hurayrah (may Allah be pleased with him) who narrated that the Prophet (peace be upon him) said: Do not swear by your fathers, mothers, or idols; and do not swear by Allah except when you are truthful. (Related by Abu Dawud and AlNasa'y)