from
Easton's 1897 Bible Dictionary
Doors
moved on pivots of wood fastened in sockets above and below
(Prov. 26:14). They were fastened by a lock (Judg. 3:23, 25;
Cant. 5:5) or by a bar (Judg. 16:3; Job 38:10). In the interior
of Oriental houses, curtains were frequently used instead of
doors.
The entrances of the tabernacle had curtains (Ex. 26:31-33,
36). The "valley of Achor" is called a "door of hope," because
immediately after the execution of Achan the Lord said to
Joshua, "Fear not," and from that time Joshua went forward in a
career of uninterrupted conquest. Paul speaks of a "door opened"
for the spread of the gospel (1 Cor. 16:9; 2 Cor. 2:12; Col.
4:3). Our Lord says of himself, "I am the door" (John 10:9).
John (Rev. 4:1) speaks of a "door opened in heaven."