The Witness of the Stars by: E. W Bullinger
                                                                           Ara (the Altar)

Here we have an altar or burning pyre, placed significantly and ominously upside down! with its fires burning and pointing downwards towards the lower regions, called Tartarus, or the abyss, or "outer-darkness." It is an asterism with nine stars, of which three are of the 3rd magnitude, four of the 4th, etc. It is south of the Scorpion's tail, and when these constellations were first formed it was visible only on the very lowest horizon of the south, pointing to the completion of all judgment in the lake of fire.
This is a coming in judgment, as is clear from the reason given in verse 4--

"For the day of vengeance is in Mine heart,
And the year of My redeemed is come.
And I looked, and there was none to help;
And I wondered that there was none to uphold;
Therefore Mine own arm brought salvation,
And My fury, it upheld Me."
Isaiah 63:4, 5

The completion of judgment, therefore, is what is pictured both by the burning pyre and the Coming One enthroned, with his threshing instrument. In Arabic it is called Al Mugamra, which means the completing, or finishing. The Greeks used the word Ara sometimes in the sense of praying, but more frequently in the sense of imprecation or cursing. This is the curse pronounced against the great enemy. This is the burning fire, pointing to the completion of that curse, when he shall be cast into that everlasting fire "prepared for the devil and his angels." This is the allusion to it written in the midst of the very Scripture from which we have already quoted, Psalm 21, where we read in verse 9 (which we then omitted)--
"Thou shalt make them as a fiery oven in the time of Thine anger:
The LORD shall swallow them up in His wrath;
And the fire shall devour them."