What he told Aisha after she answered them back
She had heard the insult and returned it with interest.
مَهْلاً يَا عَائِشَةُ، عَلَيْكِ بِالرِّفْقِ، وَإِيَّاكِ وَالْعُنْفَ وَالْفُحْشَ
Mahlan yā ʿĀʾishah, ʿalayki bi-r-rifq, wa iyyāki wa-l-ʿunfa wa-l-fuḥsh
“Gently, Aisha. Hold to kindness, and beware of harshness and foul speech.”
Where this comes from
She said: did you not hear what they said? He said: did you not hear what I said? I returned it to them, and mine is answered concerning them, and theirs is not answered concerning me.
The full narration
Narrated `Abdullah bin Mulaika:`Aisha said that the Jews came to the Prophet (ﷺ) and said, "As-Samu 'Alaikum" (death be on you). `Aisha said (to them), "(Death) be on you, and may Allah curse you and shower His wrath upon you!" The Prophet (ﷺ) said, "Be calm, O `Aisha ! You should be kind and lenient, and beware of harshness and Fuhsh (i.e. bad words)." She said (to the Prophet), "Haven't you heard what they (Jews) have said?" He said, "Haven't you heard what I have said (to them)? I said the same to them, and my invocation against them will be accepted while theirs against me will be rejected (by Allah)
Source
Ṣaḥīḥ al-Bukhārī · 6030
- Agreed upon as authentic (al-Bukhārī / Muslim)