Yahya related to me from Malik from Amir ibn Abdullah ibn az-
Zubayr from Amr ibn Sulaymaz-Zuraqi from Abu Qatadaal-Ansari that the
Messenger of Allah, may Allah bless him and grant him peace, said,
"When you enter the mosque, you should pray two rakas before you sit
down."
Muwatta Malik Book 9, Hadith 65