Chronicles II 35:14

14 And after they had prepared for themselves and for the priests, for the priests in offering the whole-burnt-offerings and the fat until night, then the Levites prepared for themselves, and for their brethren the sons of Aaron.

Chronicles II 35:14 Meaning and Commentary

2 Chronicles 35:14

And afterwards they made ready for themselves, and for the
priests
The passover lambs, and such parts of the peace offerings that belonged to them:

because the priests the sons of Aaron were busied in offering
burnt offerings;
such as are before said to be removed or separated for that purpose:

and the fat;
of the peace offerings that was to be burnt: and this employed them

until night;
so that they could not prepare the passover for themselves:

and therefore the Levites prepared, not only for themselves, [but] and
[also] for the priests the sons of Aaron; who were otherwise engaged in the service of the day.

Chronicles II 35:14 In-Context

12 And they prepared the whole-burnt-offering to give to them, according to the division by the houses of families, to the sons of the people, to offer to the Lord, as it is written in the book of Moses.
13 And thus till the morning. And they roasted the passover with fire according to the ordinance; and boiled the holy in copper vessels and caldrons, and went on well, and they quickly served all the children of the people.
14 And after they had prepared for themselves and for the priests, for the priests in offering the whole-burnt-offerings and the fat until night, then the Levites prepared for themselves, and for their brethren the sons of Aaron.
15 And the sons of Asaph the psalm-singers at their post according to the commands of David, and Asaph, and Aeman, and Idithom, the prophets of the king: also, the chiefs and the porters of the several gates; —it was not for them to stir from the service of the holy things, for their brethren the Levites prepared for them.
16 So all the service of the Lord was duly ordered and prepared in that day, for keeping the passover, and offering the whole-burnt-sacrifices on the altar of the Lord, according to the command of king Josias.

The Brenton translation of the Septuagint is in the public domain.