Than Salak
Than Salak or Thambun Salakhaphat is a Lanna tradition of merit making to monks by means of drawing a lottery to prevent people from picking out their favorite monks to give offerings to. The terms used to refer to this ceremony in the Lanna dialects vary depending on the region, for example, kin kuai salak or kin salak or tan kuai salak.
Actually, this has been an ancient Buddhist custom since the Lord Buddha’s time. When he was residing at Chetawan Mahawihan, a female demon initiated an alms offering to the monks by drawing a lot or lottery so that none could pick and choose which items one favored or go by the value of the item.