Kaufman, Stephen A, “An Emphatic Plea for Please,” Maarav 7 (1991), 195-198.
In this short article, Dr Kaufman argues for the traditional rendering of the particle נָא as ‘please’, against the study of T.O. Lambdin who suggested that the particle marks the command as being a logical consequence of the previous statement or the general situation. Waltke-O’Connor also quotes Lambdin, apparently approvingly, in their short section on the particle.Dr Kaufman sees three compelling arguments for the interpretation ‘please’: First, there is no significant way left in Biblical Hebrew to say ‘please’ if not with נָא. Second, נָא never appears when the focus of the command is a third party suggesting that it has to do with the relationship between speaker/addressee rather than the logical nature of the command. The third argument is the most interesting and relates to the nature of the so-called nun energicum.The particle נָא can be used after interrogative and presentative particles such as אִם, אַיֵּה, and הִנֵּה, but most of the time it appears after imperatives and the other phrase-initial verbal forms which belong to the “imperative modal set” such as cohortatives, jussives, and rarely even the perfect consecutive. Although it is now an independent particle, many scholars have suggested that it may have originally been a part of the earlier “energic” modal preformative verb form, *taqtulanna. At some point scribes began to separate the n(n) from the verb by a word divider as was the case at Ugarit (see H Gottlieb, “The Hebrew Particle nâ,” Acta Orientalia 33 (1971): 47-54).Based on the so-called subjunctive modes reflected in Amarna Akkadian and the “energic” mode of Arabic, Lambin, and others such as Gottlieb, Moran, and Rainey, have argued that the earlier “energic” forms of the preformative were subjunctives and marked grammatical subordination. Thus it can be seen why the idea of logical succession would be a more appealing explanation of נָא then entreaty. However, Dr Kaufman argues that this understanding of the “energic” ending is mistaken.
Preformative (and imperative) verbal forms in Arabic and Northwest Semitic ending in -(an)na are not ‘energic,’ ie they are not emphatic. They do, rather, express petition, doubt, or question – a softening rather than a strengthening!”
Thus נָא is descendent of the split of the -anna ending into -ā (the origin of the cohortative) and nnā. This implies that the primary use of the Hebrew cohortative by itself is to express a wish or request for permission even without the accompanying נָא. The long form of the imperative, with the -ā ending, can also be seen as equivalent to the imperative + נָא, a more polite form. Lastly, this explains why the -n forms of the pronominal suffixes (usually explained as preserving the so-called long imperfect in contrast to the short jussive or preterite forms) can also occur with the imperative marking the long imperative:
שִׁלְחָ֣ה וְקָחֶ֔נּוּ 1 Sam 16:11
“go and fetch him, please”