It is difficult for me to find the reference about Gautama Buddha wore robe made from cloth which was wrapped to a death body. Which part of Sutta do I have to reference?
Can we calculate how long Buddha wore this?
It is in SN 16.11.
‘Your outer robe of patches is soft, Kassapa.’–‘Venerable sir, let the Blessed One accept my outer robe of patches, out of compassion.’–‘Then will you wear my worn-out hempen rag-robes? ’–‘I will, venerable sir.’ Thus I offered the Blessed One my outer robe of patches and received from him his worn-out hempen rag-robes.
However, the English translation doesn't mention that the Buddha wore a cloth wrapped to a dead body instead it just mentions worn-out hempen rag-robes. In the pali version it says the robe was paṃsukūlāni (rags discarded on the ground).
The Buddha has obtained it from the dead body of a servant named Punna lying in the cemetery (this part is in the commentary). He wore this robe until he exchanged it with Maha Kassapa.