Umayr reported,

He saw the Messenger of Allah ﷺ praying for rain near the Stones of Oil, close to Zawra, standing as he supplicated for rain, raising his palms without lifting them above his head, with the inner sides of his palms facing his face.

Azami 2961

Sahih

عن عمير مولى أبي اللحم

أنه رأى رسول الله ﷺ يستسقى عند أحجار الزيت قريبا من الزوراء قائما يدعو يستسقي رافعا كفيه، لا يجاوز بهما رأسه مقبل بباطن كفيه إلى وجهه.

الأعظمي 2961صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Prayer
Chapter
Prayer for rain
Section
Raising the hands in supplication during the rain prayer
Numbering
Jami al-Kamil 2961 (2nd edition)
Azami 2961