28. And David answered and spoke, “Call for me Beersabee.” And she came before the king and stood before him.
29. And the king swore and said, “As the Lord lives, who ransomed my life from every trouble,
30. “just as I swore to you by the Lord, the God of Israel, saying, ‘yes, Solomon, your son, will reign after me and will sit upon my throne in my stead.’ For thus I will this day.”
31. And Beersabee bent down, face upon the ground, and prostrated to the king and said, “May my lord, the King, David, live in eternity!”
32. And the king, David, said, “Call for me Sadok the priest and Nathan the prophet and Banaias son of Iodae.” And they came before the king.
33. And the king said to them, “Take the servants of your lord with you and put my son Salomon on my mule and lead him down to Gion.
34. “And anoint him there, Sadok the priest and Nathan the prophet, to king over Israel, and blow in the horn and say, ‘Long live the king, Salomon!’
35. And he will sit upon my throne and he will reign in my stead. And I have commanded (him) to be in rulership over Israel and Judah.”
36. And Banaias son of Iodae answered and said, “So be it! So shall the Lord, the God of my lord the king, affirm.
37. “As the Lord was with my lord the king, so may he be with Salomon and make his throne greater than the throne of my lord, the king, David!”

From the “12th-century Romanesque bible of San Isidoro de León” (1162).
Wikimedia Commons. Public Domain.
Comments on the Text
Here we have another longer passage of text, but, again disregarding orthographic variation in proper nouns, without too many substantial differences between the Greek and the Hebrew versions. Verse 28 is missing the title “king” on two occasions, once at the beginning before David’s name and then again at the end, naming to whom Beersabee prostrated. These could be minor stylistic changes or oversights, though it is still possible that the Septuagint preserves older readings (being shorter). That could have literary-critical implications.
Over a more substantial nature is the absence of the opening of v. 35 when contrasted with the Hebrew. This Greek version mentions no ascending or entering. That is, it suggests that Solomon should sit on the throne of David at the well of Gihon. That makes little sense. Presumably for that reason, later editors “corrected” the Hebrew text to bring Solomon back up to the palace and the throne there.
Again in v. 35, at the end of the verse, the Greek text is missing the preposition “over” before “Judah”, paralleling the phrase “over Israel.” Taking a maximalist approach to this variation could imply that the Greek text (or its Vorlage) regarded “Israel and Judah” more as a unity. The Hebrew text separates them somewhat, defining them more clearly as two distinct units over which one might reign, “over Israel” and “over Judah.”
Finally, verse 36 concludes with Banaias wish that the Lord “affirm” David’s commands instead of merely “speak” them. Probably this difference goes back to a different Greek Vorlage or an error by the translation. While these two things may be quite different in English, the difference in Hebrew really only revolves around one letter. And it would represent a more clear parallel with the opening of the phrase. That is, while it remains possible that the Greek is a mistake, the better option is that attests a different, probably older Hebrew parent text.