Tafsir of Al-Waqi'ah 56:6

(Then it became) – meaning it became, as a result of that – (dust) – [meaning] fine particles – (scattered) – [meaning] dispersed. According to the majority, the intended meaning is dust in the absolute sense. Ibn Abbas said: It is that which rises in the sunbeams when they enter through a niche. In another narration from him, it is that which flies off from a fire when it blazes.

Al-Nakha'i recited it as munbattan (with a terminal 'ta' with two dots above), from al-batt, meaning "the cutting." The intended meaning is the same as al-bath (with the three-dotted 'tha').