Srimad-Bhagavatam: Canto 3 - Chapter 1 - Verse 40

Sanskrit:

यथोल्मुकाद्विस्फुलिङ्गाद्धूमाद्वापि स्वसम्भवात् ।अप्यात्मत्वेनाभिमताद्यथाग्नि: पृथगुल्मुकात् ॥ ४० ॥

ITRANS:

yatholmukād visphuliṅgāddhūmād vāpi sva-sambhavātapy ātmatvenābhimatādyathāgniḥ pṛthag ulmukāt

Translation:

The blazing fire is different from the flames, from the sparks and from the smoke, although all are intimately connected because they are born from the same blazing wood.

Purport:

Although the blazing firewood, the sparks, the smoke and the flame cannot stay apart because each of them is part and parcel of the fire, still they are different from one another. A less intelligent person accepts the smoke as fire, although fire and smoke are completely different. The heat and light of the fire are separate, although one cannot differentiate fire from heat and light.