A - never mention a possibility of something going wrong for someone
Because Hashem may cause your words to come true.
Kesubos 23a
B- don't open your mouth for the satan
The question is when do we apply rule *A* and when rule *B* ?
See Moed Katan 18a the top Tosfos & the Maharsha.
Either way we must be careful before speaking. Words are not cheap , they may be very costly. Ask a lawyer for his rates.
Now may be a good time for a gem of Torah study.
www.GemsofTorah.com
