Rashi: When your burning will extinguish, smoke will rise and cover Shamayim, and the luminaries will be darkened. I.e. all who hear about you will mourn and be astounded. Everyone will worry about himself, and say 'the destroyer will come also upon us!'

Radak: It is as if [your burning] is a lamp, due to its great size. When it extinguishes, the smoke will cover Shamayim, and it will not be seen. This is an exaggeration for how great the affliction will be.

Malbim: Now the Navi describes the second fall of Egypt, in its land; this was prophesized above, starting with 29:8. The Mashal here is based on the Egyptian belief that their star rules in Shamayim, and its light will never be dimmed. When the cloud will darken it and it begins to extinguish, there will be great smoke, and all luminaries of Shamayim will be dimmed. (In Egypt, the sky is always clear; there is never a cloud or rain.) "V'Chiseisi b'Chabosecha" is a Mashal for the first Churban in Eretz Mitzrayim ? its light partially extinguished.

Malbim: This is a metaphor that also below, all Egypt's helpers ceased, and several nations with them.