Musar על מכות 33:12

Commandment 448 prohibits the eating of קדשים קלים, i.e. offerings some parts of which may be consumed by the owner, before completion of the sprinkling of the blood on the altar. This is also derived from 12,17. The word ונדבותיך is understood as basically superfluous and therefore used to refer to premature consumption of freewill offerings such as תודה and שלמים.