Saale ko jo tu gaaliyan nikalta hoga, Rahu nau teri kismat ko galta hoga.
If you hurl abuses at your brother-in-law, Rahu in the 9th will melt/destroy your destiny.
This is a highly specific and critical Lal Kitab warning regarding family relations and planetary energies.
In Lal Kitab, different relatives represent different planets. The brother-in-law (wife's brother / "Saala") is strongly connected to the energy of Mercury and Rahu.
Dr. Sharma warns that if a person with Rahu in the 9th house (the house of destiny) constantly fights with, insults, or abuses their brother-in-law ("saale ko gaaliyan nikalta"), they are directly triggering a curse. This toxic behavior will literally "melt" or destroy their own luck and destiny ("kismat ko galta hoga"). Treat your in-laws with respect to protect your own future.