Sayyiduna Abdullah bin Zayd al-Ansari (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) went out to the prayer ground to ask for rain, and when he (peace and blessings be upon him) intended to supplicate, he turned his face towards the qiblah and turned his cloak around.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الاستسقاء / 6412