Verses 18-19 add four more laws that are not directly related to the preceding verses, but they deal with the proper way to present offerings to God. Yahweh is still speaking. You shall not offer is the categorical form of law, using the singular you. Offer is from the same word as sacrifice in the blood of my sacrifice. Its basic meaning is to slaughter, but here it means to present to the LORD an animal that has been slaughtered. (See the comment on “sacrifice” at 3.18b.)

The blood of my sacrifice is quite literal and unclear. My sacrifice, of course, refers to the animal that is slaughtered and offered to Yahweh according to the proper ritual. The blood of the animal was the most important part, and it had to be disposed of properly. (See, for example, Lev 1.5, 11, 15, and elsewhere.) So Good News Translation‘s “when you sacrifice an animal to me” is not recommended, since it makes no mention of the blood. A better model is “when you sacrifice an animal and offer its blood to me….”

Leavened bread was bread (or any other food) made with yeast. New Revised Standard Version has “anything leavened,” and New International Version has “anything containing yeast.” (See the comment on unleavened bread at 12.15.) It was permitted for some sacrifices (see Lev 7.13 and 23.17), but it was never to be burned on the altar. For most sacrifices only unleavened bread was used, possibly because the leaven represented the vital force of the vegetable world, just as blood represented the vital force of the animal world. The preposition with may also mean “when” or “in addition to.” Translator’s Old Testament has “together with,” and Revised English Bible has “at the same time as.” An alternative model for the first part of this verse is “Do not offer bread made with yeast when you slaughter an animal and offer its blood to me.”

Or let the fat of my feast remain is literally “and the fat of my feast will not remain.” The fat was the suet, or hard fat around the kidneys and loins of the animal. It was never eaten but had to be burned as an offering to God. (See Lev 3.15-17; 7.23-24.) My feast uses the same word for pilgrim festival as in verses 14-16. It refers to “the animals sacrificed to me during these festivals” (Good News Translation). Until the morning means that the fat had to be completely burned before the following morning. An alternative model is the following: “Make sure that you burn all the fat of that animal the same day” (similarly Contemporary English Version).

Quoted with permission from Osborn, Noel D. and Hatton, Howard A. A Handbook on Exodus. (UBS Helps for Translators). New York: UBS, 1999. For this and other handbooks for translators see here .