Honoring Father, Mother, and Grandfather
Question
1. If the father says one thing and the mother another, whom must one listen to? 2. If the father says one thing and the grandfather another, whom must one listen to? 3. Is there an obligation at all to honor one’s grandfather?
Answer
Dear …!
1. If the father wants one thing and the mother wants something else at the same time, the father should be prioritized. However, if the father says not to obey the mother, it is forbidden to listen to him.
2. The honor of the father precedes the honor of the grandfather.
3. There is a commandment to honor the grandfather — the father's father. Halachic authorities are divided on whether there is a commandment to honor one’s mother's father.
Source
Shulchan Aruch, Section Yoreh Deah, chapter 240, Paragraph 24.