Malbim: Amidst your great sin in trade, you profaned your Mikdash (refer to 28:18:2:3).

Rashi: It is Kedushasecha (your Kedushah).

Radak: Your castle. This is like Mikdash Melech Hu" (Amos 7:13). Your theft and sin caused you to profane and destroy your castle.

Malbim: You had a merit in the Beis ha'Mikdash [for helping to build it]. Since you rejoiced over its destruction, you lost this merit.

Rashi: The haughty words that left your mouth, to say "Kel Ani" (2).

Rashi citing Targum Yonasan: Nations strong like fire will come due to the liability of your Mezid sin.

Radak: Fire is a metaphor for sin.

Malbim: This is Midah k'Neged Midah ? just like you rejoiced over burning of the Mikdash, fire will consume you.

Radak: It is because it says "Achalascha"; what fire consumes, it becomes ashes. This entire Nevu'ah is past tense used in place of future; this is common in Nevu'ah.

Malbim: You will be ashes on the ground.