A witness cannot be asked to explain the statement of a third party or the document of a third party of which the witness is not a part.
Section 145 of the Evidence Act permits a witness being cross-examined as to previous statement made by him and not by a third person.
Supreme Court
Makhan Lal Bangal vs Manas Bhunia & Ors.
Decided on 3 January, 2001
AIR 2001 SC 490, JT 2001 (1) SC 252 :
2001 (1) SCALE 11.