Yeah, so says Muhammad. He also said the sky will become weak and crack open, and that the sky has to be held up with invisible pillars. I have no idea why the word pillars ever needed to be mentioned unless he thought the sky was some sort of structure and that pillars are needed to hold structures up. So I don't take anything that he said very seriously.
Neither Qur'aan nor he said that the heavens were held up with pillars.
The first part of Surah 13:2 confirms that:
"God is the One Who raised the heavens without a pillar as you can see."