Translating Presuppositions and Exodus 18:2-3

The past few days, I attended the Bible Translation Conference in Dallas. The last paper/presentation I heard was Paul Kroeger's "Translating Presuppositions," and it was very enjoyable (and helpful!). The following points are from some of his presentation and handout:

New information can be packaged as if it were old info. For example:

• Two people meet each other for the first time and one asks the other to go with him somewhere. The second one responds and says, "No, I have to pick up my sister."

"My sister" is presented as shared knowledge, but before the utterance, the first person did not know the second one had a sister. This is therefore a case where the utterance is treated as though shared info, and not controversial.

Definition of presupposition from SIL Online Glossary of Linguistic Terms:

A presupposition is background belief, relating to an utterance, that

• must be mutually known or assumed [or--Kroeger argued--considered not controversial/challengeable] by the speaker and addressee for the utterance to be considered appropriate in context...

Exodus 18:2-3a contains an informative presupposition:

Now Jethro, Moses' father-in-law, had taken Zippo'rah, Moses' wife, after he had sent her away, and her two sons...

The clause "after he had sent her away" is presented as though the reader already knows this happened, when in fact, this is the first we hear of it in the OT narrative.

Translations handle the presupposition in various ways.

• NCV: Now Moses had sent his wife Zipporah to Jethro, his father-in-law, along with her two sons.
• NIV: Moses had sent his wife Zipporah to his father-in-law. So Jethro welcomed her...
• CEV: In the meantime, Moses had sent his wife Zipporah and her two sons to stay with Jethro, and he had welcomed them in.
• NLT: Earlier, Moses had sent his wife, Zipporah, and his two sons back to Jethro, who had taken them in.
• Brazilian Portuguese "Today's Language" Version (Eng. BT): So he went to the place where Moses was, bringing Zipporah, Moses' wife. Moses had sent Zipporah and her two sons to the house of Jethro.

Alternative rendering as conventional implicature:

• UBS Handbook on Exodus (option b): So Jethro came to Moses bringing with him Moses' wife Zipporah, whom Moses had left behind.
• Indonesian Terjemahan Baru (Eng. BT): Then Jethro, Moses' father-in-law, brought Zipporah, Moses' wife--who had earlier been sent back/ordered to return by Moses-

Some options for translation:

1. As a separate assertion (i.e., Moses had sent away his wife; e.g., NIV) . But the SL treats it as background info, and the main point of the SL should the main point of the TL if following Callow 1974: 59.
2. As a parenthetical (i.e., "....--Moses had sent her away--...")
3. As a relative clause (i.e., "whom Moses had left behind" (UBS Handbook)

Some questions to ask of the translation option chosen:

• Does repackaging the information go too far away from the meaning of the SL?
• What is the cost-benefit analysis of the translation decision?