What does Hebrews 9:4 mean by saying the Holy of Holies 'had' an altar of incense?

Question

The altar of incense was outside the Holy of Holies but in some sense Hebrews seems to group it along with those things inside the Holy of Holies. What does this grouping mean? Why is the altar of incense grouped with the Holy of Holies?

Behind the second curtain was a second section called the Most Holy Place, having the golden altar of incense and the ark of the covenant covered on all sides with gold, in which was a golden urn holding the manna, and Aaron 's staff that budded, and the tablets of the covenant. (ESV, Hebrews 9:3-4)

Answer 1

The Greek text of Heb. 9:4 states,

^Δʹ χρυσοῦν ἔχουσα θυμιατήριον καὶ τὴν κιβωτὸν τῆς διαθήκης περικεκαλυμμένην πάντοθεν χρυσίῳ ἐν ᾗ στάμνος χρυσῆ ἔχουσα τὸ μάννα καὶ ἡ ῥάβδος Ἀαρὼν ἡ βλαστήσασα καὶ αἱ πλάκες τῆς διαθήκης ^{TR, 1550}

which may be translated into English as,

⁴ having a golden «θυμιατήριον», and the ark of the covenant overlaid round about with gold, in which [there was] a golden pot having the manna, and the rod of Aaron that budded, and the tablets of the covenant,

(to be edited)

Answer 2

Rabbinical tradition at this time believed all three articles were in the ark: the 10 commandments, Aaron's rod that budded and the golden jar of manna, although we see in Exodus 16:34 God told Moses to put the golden jar of manna BEFORE the ark, Numbers 17:10 The Lord told Moses to put Aaron's rod that budded BEFORE the ark and Deuteronomy 31:26 where the Book of the Law (Pentateuch) was to be placed BEFORE the ark (this article is not even mentioned in Hebrews 9:4).

It is believed that at the time the book of Hebrews was written (before the destruction of the Temple in AD 70) the Holy of Holies was empty.
As Josephus writes: "But the inmost part of the temple of all was of twenty cubits. This was also separated from the outer part by a veil. In this there was nothing at all. It was inaccessible and inviolable, and not to be seen by any; and was called the Holy of Holies." Wars of the Jews V, v 5

Therefore, it is concluded by some that the description given in Hebrews 9:4 was taken from Rabbinical tradition.