Which relatives are disqualified from testifying according to Torah law (d'orayta)?
The Torah disqualifies only paternal relatives. Maternal relatives and relatives by marriage are disqualified only by Rabbinic decree.
Question 2
May two twin brothers who converted to Judaism testify for each other?
A convert is considered k'katan she'nolad — like a newborn child. All prior family relationships are severed upon conversion, so even twins may testify for each other.
Question 3
If a person is disqualified from testifying on behalf of a man because that man is married to his relative, what happens if the wife dies?
Once the wife dies, the marital connection that caused the disqualification is severed. The former in-law is considered 'released' and is once again an acceptable witness.
Question 4
Why does the Torah disqualify relative testimony?
Rambam explicitly states that the disqualification is not because we assume relatives love each other — it is a Scriptural decree (gezerat katuv). That is why friends and enemies, who have emotional bias, remain valid witnesses.
Question 5
If two women are second-degree relatives of each other (sheni b'sheni), may their husbands testify for each other?
When two women are second-to-second (sheni b'sheni), their husbands may testify for each other. But if the women are first-to-first (e.g., mother and daughter), their husbands cannot testify for each other.