Fla. Stat. § 132.17

The resolution authorizing refunding bonds may assign, pledge, or set aside as a trust for the payment of principal or interest of refunding bonds or for a sinking fund for the bonds, subject to prior liens or contract obligations, and on, or subject to, such terms and conditions as may be stated, any unpaid taxes or assessments whether due or to grow due, and any revenues due or to grow due, or proceeds of sale of improvements or properties of the unit. The resolution authorizing the bonds may contain agreement to collect and pay over the moneys derived from such source.