Isa or Is represents a warning to leave things as they are for the time being. Isa implies that taking something further or taking an action at this time is akin to walking on thin ice and will create unnecessary difficulties.
The Isa rune is the same in either upright or reverse position and is a strong warning to the stand still, stay where you are, and take no action. It can also mean cancelling plans due to unforeseen circumstances or changes.
In love and light