'Abdullah bin Saa-ib Radiyallahu'Anhu reports:
"Rasulullah Sallallahu 'Alayhi Wasallam performed four rak'ahs after zawaal before the zuhr salaah, and used to say: 'The doors of the heavens open at this moment. I like that a good deed of mine ascend there at this moment'". (IT)
English reference (IT): Book 40, Hadith 278 (IT)
Arabic reference (IT): Book 41, Hadith 295 (IT)