Hadith.4305 - Al-Sakuni narrated from Imam Jafar ibn Muhammad Al-Sadiq عليه السلامwho said:
"If a man says, 'I swear' or 'I have taken an oath,' it is of no consequence until he says, 'I swear by Allah سبحانه وتعالى' or 'I have taken an oath by Allah سبحانه وتعالى.'"