Similar to the phrase On Jah. Which is used to confirm you are serious in a situation. However, swearing on jahskellini is used on much more formal occasions for serious matters. Can also be used as a way to confirm something someone has said if asked as a question
Guy 1: "Nigga my grandma just fucking died"
Guy 2: "On jahskellini??"
an awsome,sweet,beutiful,perfect girl that is very loving and awesome. if you ever meet a jashelle, take amazing care of her. try not to loose her. she’s very special.
Jahsel is the sweetest and most beautiful girl on the planet, at times she feels like everyone around her is completely useless and she has to do everything herself but she can handle it because she is such a bad bitch!... Jahsel will melt people's hearts in an instant boy or girl. If you ever meet a Jahsel, just know you have been blessed with a sight of a beautiful angel.
guy: "that girl is ridiculously Hot"
guy 2: "that girl is a Jahsel.