Is saying "yes" in response to someone's "I swear to God" considered an oath for me?

The listener's statement "By Allah?" is an interrogative question, meaning: "Do you swear by Allah concerning this statement?" The answer "Yes" is considered an affirmation of what the question implies, because "the question is repeated in the answer." The jurists have agreed that the words "Na‘am" (yes), "Ajal" (indeed), and "Bala" (yes, on the contrary) when given as answers to a question, are considered an affirmation of what is in it, because they are explicit forms of affirmation. This includes the rulings concerning oaths; so if an oath is presented to a person and he says "Yes," he is considered to have sworn.