Sahih Muslim Book 004, Hadith Number 1978.
Chapter : Mention of the torment of grave in eclipse prayer.
Asma' said: I came to 'Aisha when the people were standing (in prayer) and she was also praying. I said: What is this excitement of the people for? And the rest of the Hadith was narrated like one, (narrated above). 'Urwa said: Do not say Kasafat-ush-Shamsu, but say Khasafat-ush-Shamsu.