How to tween 1 point of an object

I have a sword but when the model rotates it rotates from the middle even tho it should rotate from the handle

I think you can use the PivotOffset property for this

how would you go using this in a tween?

Tweening with Pivots is a bit weird but I believe this works, if there is an error just tell me:

{CFrame = part:GetPivot() * Cframe.angles(0, 0, math.rad(90))} -- set this to the tween destination

Just for clarification you can change the CFrame.angles to whatever you need and the part variable is the part getting tweened.