It is just as if a man were to draw out a reed from its sheath. He might think: This is the reed, this is the sheath, reed and sheath are different. Now the reed has been pulled from the sheath. … In the same way a monk with mind concentrated directs his mind to the production of a mind-made body. He draws that body out of this body.
M. Walshe, trans. (1987), Sutta 2 (Samaññaphala Sutta), verse 86, p. 104 - Digha Nikaya