When God calls Samuel it seems like he sleeping inside the Temple/Tabernacle were the ark of God was
1 Samuel 3:2-3 NASB
2 But it happened at that time as Eli was lying down in his place (now his eyesight had begun to be [b]poor and he could not see well), 3 and the lamp of God had not yet gone out, and Samuel was lying down in the temple of the Lord where the ark of God was,
But according to the design given Moses which is described in the book of Hebrews there were only two rooms the holy place and the holy of holies which housed the vessels of God.There is no mention of anyone sleeping in those rooms.
Hebrews 9:15 NASB
9 Now even the first covenant had regulations for divine worship and the earthly sanctuary. 2 For a [a]tabernacle was equipped, the [b]outer sanctuary, in which were the lampstand, the table, and the [c]sacred bread; this is called the Holy Place. 3 Behind the second veil there was a [d]tabernacle which is called the Most Holy Place, 4 having a golden [e]altar of incense and the ark of the covenant covered on all sides with gold, in which was a golden jar holding the manna, Aaron’s staff which budded, and the tablets of the covenant; 5 and above it were the cherubim of glory overshadowing the [f]atoning cover; but about these things we cannot now speak in detail.
.By the time there were at Shiloh it is said Samuel was sleeping inside the Temple/Tabernacle which also housed the Ark of the covenant which somehow points to the holy of holies
Did Samuel sleep in the holy of holies at Shiloh?