What to say when the greeting is not friendly
Aisha wanted to answer them in kind and was told not to.
إِنَّ الْيَهُودَ إِذَا سَلَّمُوا عَلَيْكُمْ يَقُولُ أَحَدُهُمُ السَّامُ عَلَيْكُمْ فَقُلْ عَلَيْكَ
When they greet you, say: and upon you. Aisha said: rather, and upon you death and the curse. He said: gently, Aisha. Allah loves gentleness in all matters.
He did not defend them. He corrected the way she answered them.
The full narration
Ibn 'Umar reported Allah's Messenger (ﷺ) as saying:When the Jews offer you salutations, some of them say as-Sam-u-'Alaikum (death be upon you). You should say (in response to it): Let it be upon you
Source
Ṣaḥīḥ Muslim · 5654
Ṣaḥīḥ
- Agreed upon as authentic (al-Bukhārī / Muslim)