Let no one does not mean “Do not permit anyone to become” but “No one should become.”

Immoral means “sexually immoral,” King James Version “fornicator,” probably in the literal sense, rather than “unfaithful to God.” In a number of languages sexual immorality is described as “sleeping with a woman who is not your wife.” But such immorality is frequently spoken of by means of idioms, for example “to live like a dog,” or “to chase after women,” or “to be always looking for vulvas.”

Unspiritual means “having no respect for holy things”; Bible en français courant; similarly Parola Del Signore: La Bibbia in Lingua Corrente. Die Bibel im heutigen Deutsch links this with the rest of the sentence: “Because he did not honor God, he sold his privilege as elder son….”

A single meal is emphatic, but King James Version‘s “one morsel of meat” (that is, “food”) goes too far; see Genesis 25.33-34.

The use of a term such as sold may suggest some kind of monetary payment. But since only an exchange was involved, it may be necessary to translate who for a single meal sold his rights as the older son as “who in exchange for just one meal gave up what was coming to him as the older son” or “… the older brother.”

Quoted with permission from Ellingworth, Paul and Nida, Eugene A. A Handbook on The Letter of the Hebrews. (UBS Handbook Series). New York: UBS, 1983. For this and other handbooks for translators see here .