Mahāparinibbāna Sutta 6.23.1

6.23.1

Jhāyamānassa kho pana bhagavato sarīrassa yaṃ ahosi chavīti vā cammanti vā maṃsanti vā nhārūti vā lasikāti vā, tassa neva chārikā paññāyittha, na masi;

And when the Buddha’s corpse was cremated no ash or soot was found from outer or inner skin, flesh, sinews, or synovial fluid.