Is the Saying of People: "I have Sworn Upon You" an Oath?
Question :
Many times I say such words as these and they are: "I have sworn to you that you should not do such-and- such." And since sometimes I do not implement it, am I guilty of sin? And has an oath been made? Advise me and may Allah reward you.
Answer:
It would appear that this wording does not fall under the ruling of an oath. Swearing is avowing by one of the Names of Allah, Most High or one of His Attributes, such as your saying: "By Allah", "By the Lord of Might", "By the Power of Allah and His Majesty", or your saying: "I have sworn by Allah" and the like. As for saying: "I have sworn to so-and-so" there is no atonement necessary for it, but it is more prudent to fulfill one's oaths as well as those statements that resemble oaths.
Source:
Ibn Jibreen
Fatawa Islamiyah, Vol. 6 Pages 366-367