When taking an oath, the Prophet (ﷺ) very often used to say, "No, by Him Who turns the hearts."
Sahih al-Bukhari Book 82, Hadith 23
← Previous Hadith The Prophet (ﷺ) said, "Take refuge with Allah from the difficulties of severe calamities, from having an evil end and a bad fate and from the malicious joy of your enemies."

Sahih al-Bukhari Book 82, Hadith 22 Next Hadith → The Prophet (ﷺ) said to Ibn Saiyad, "I have kept for you a secret." Ibn Saiyad said, "Ad-Dukh." The Prophet said, "Keep quiet, for you cannot go beyond your limits (or you cannot exceed what has been foreordained for you)." On that, `Umar said (to the Prophet (ﷺ) ), "Allow me to chop off his neck!" The Prophet said, "Leave him, for if he is he (i.e., Ad-Dajjal), then you will not be able to overcome him, and if he is not, then you gain no good by killing him."

Sahih al-Bukhari Book 82, Hadith 24