1. And the king, David, (was) older, advanced in days. And they clothed him with garments. And he did not warm up.
2. And his servants said, “they should seek for our lord the king a virgin, a young woman. And she will attend to the king and will be a warmer (for) him and will be laid with him and warm our lord the king.”
3. And they sought a good young woman from Israel’s whole territory and found Abishak the Somanite and brought her to the king.
4. And the young woman (was) good, even very. And she warmed the king and served him. And the king did not know her.

Comments on the Text
The commentary here will focus primarily on the distinctions in this version when contrasted with the Hebrew. It is helpful to begin this process, just as with the Hebrew, with a short text.
The first verse presents essentially a word for word translation of the Hebrew text known in the Masoretic Text. One element is missing: the concluding preposition with an object. The Greek translated the Hebrew phrase ולא יחם לו (literally: “not was it warm to him”) with the passive voice, leaving out the prepositional phrase. Based on the kaige translation technique attested in the best witness of this text in this portion of Kings, that is somewhat surprising (cf. this post for further background, if necessary).
The second verse has a few differences from the Hebrew text. First, it is again missing the prepositional phrase referring to the king. Secondly, it refers to “our lord” instead of “my lord” twice in Greek, which makes more sense in the context. Either the Greek text accommodates the context (lectio facilior) or the Hebrew is corrupt (the interpretation I prefer). The distinction between the two forms is insubstantial (אדני as in the MT vs. אדננו presupposed by the Greek). It is not said that the virgin to be sought for the king should sit in his lap in the Greek, as in the Hebrew.
Verse three appears to presume the same Hebrew text as found in the Masoretic version, albeit one interesting interpretive choice and some conforming of the names to the Greek alphabet. One notices, first, that the young woman’s name and place of origin are different in Greek: She is now Abisak the Somanite. The most conspicuous differences are the sibilants, since Greek has a paucity of sibilants when contrasted to the Semitic text it is translating (i.e., there is no “sh” sound in Greek). The terminal consonant is /k/ in Greek, but /g/ in Hebrew, a not uncommon replacement of sound. Finally, one could read the Septuagint as granting this young more competence to actually attend to the king, when contrasted to the Hebrew text. She is regarded as “good” (καλην), which can mean “beautiful,” but also “wise.”
This interpretation is also possible in v. 4, which includes the same term. Otherwise, v. 4 presents an essentially identical text in Greek and Hebrew. Perhaps one noteworthy term: when referring to her serving the king, the Greek uses the root behind the English term for “liturgy” (λειτουγεω).