Is it obligatory to fulfill an oath sworn in the form of "By the right of There is no god but Allah and by the right of Muhammad is the Messenger of Allah, if you feel that I am not playing games with you, give me your phone number," knowing that giving the number might cause problems?

Upholding an oath is a right a Muslim has over his brother, but scholars have differed on whether the phrases "by the right of 'There is no god but Allah'" or "by the right of Muhammad, peace be upon him" constitute an oath. Some consider it an oath if intended as such, while others do not consider it an oath at all. Therefore, the questioner is not obliged to uphold an oath made using these phrases, especially if it leads to a problem.