Digha Nikaya 1:1474
SUJATOJhāyamānassa kho pana bhagavato sarīrassa yaṁ ahosi chavīti vā cammanti vā maṁsanti 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.