What is the legal effect when a partner testifies to a debt owed to a partnership, where he has a share?
General Chapter
Al-Mughni
Book of Judicial Rulings
Primary text
If a witness testifies to a matter where he has a partial interest, such as a partner testifying to his partner concerning partnership money, or testifying against Zayd regarding a house that belongs to him and 'Amr, his entire testimony is nullified. The basis for this is that any testimony partially influenced by suspicion invalidates the whole testimony, similar to a manager testifying to the owner regarding funds from the investment. This rule applies also if he testifies to a debt owed to his father and a non-relative, or testifies to a matter where part of the testimony is rejected.
Supporting text
Al-Shafi'i holds two opinions on this: one aligns with the view that the testimony is nullified entirely, and the second opinion is that his testimony for the other party is valid because he is a non-partner concerning that specific right, so his testimony is valid for the other party as if he had no share in the matter whatsoever.