Why did Abraham laugh?
Rashi- This word ויצחק Onkelos translates by וחדי which signifies joy (“and he rejoiced’’) but the similar verb in the case of Sarah (ותצחק Genesis 18:12) he translates as meaning laughter. From this you may understand that Abraham had faith and rejoiced, and that Sarah had no faith and sneered, and that is why God was angry with Sarah (when she laughed) but was not angry with Abraham.
I surmise that for Rashi the laughter of Abraham caused embarrassment. I disagree that the reason for the laughter was different. Both laughed since the way of life in those days and also nowadays is that when a man is 100 years old and his wife turned just 90-the chance for bringing a child to this world is 0%. However, this is a miracle. Let’s not forget it. By the way, both Abraham and Sarah laughed in their hearts.
Do you think that there’s a difference between them?