The book of Hebrews uses the Hebrew Bible as support for its arguments many times. The author cites Jeremiah 31:33 in two different places and chooses to render the verse curiously differently each time.
The first citation occurs in Hebrews 8:10:
ὅτι αὕτη ἡ διαθήκη ἣν διαθήσομαι τῷ οἴκῳ Ἰσραὴλ μετὰ τὰς ἡμέρας ἐκείνας, λέγει Κύριος, διδοὺς νόμους μου εἰς τὴν διάνοιαν αὐτῶν, καὶ ἐπὶ καρδίας αὐτῶν ἐπιγράψω αὐτούς, καὶ ἔσομαι αὐτοῖς εἰς Θεόν καὶ αὐτοὶ ἔσονταί μοι εἰς λαόν. (NA27)
For this is the covenant that I will make with the house of Israel after that time, declares the Lord: I will put my laws in their minds and write them on their hearts. I will be their God, and they will be my people.
The second citation is in Hebrews 10:16:
Αὕτη ἡ διαθήκη ἣν διαθήσομαι πρὸς αὐτοὺς μετὰ τὰς ἡμέρας ἐκείνας, λέγει Κύριος· διδοὺς νόμους μου ἐπὶ καρδίας αὐτῶν, καὶ ἐπὶ τὴν διάνοιαν αὐτῶν ἐπιγράψω αὐτούς (NA27)
This is the covenant I will make with them after those days, says the Lord: I will put My laws on their hearts and write them on their minds
For reference, Jeremiah 31:33 reads
כִּי זֹאת הַבְּרִית אֲשֶׁר אֶכְרֹת אֶת־בֵּית יִשְׂרָאֵל אַחֲרֵי הַיָּמִים הָהֵם נְאֻם־יְהֹוָה נָתַתִּי אֶת־תּוֹרָתִי בְּקִרְבָּם וְעַל־לִבָּם אֶכְתְּבֶנָּה וְהָיִיתִי לָהֶם לֵאלֹהִים וְהֵמָּה יִהְיוּ־לִי לְעָם׃ (MT)
But such is the covenant I will make with the House of Israel after these days—declares Hashem: I will put My Torah into their inmost being and inscribe it upon their hearts. Then I will be their G-d, and they shall be My people.
Why does the author of Hebrews use "house of Israel" the first time and "them" the second time? Is there textual support for the second citation? If so, which citation has better textual support? If not, why change the words of Jeremiah?