It is narrated from Sayyiduna Khallad bin Sa’ib (may Allah be pleased with him) that when the Prophet (peace and blessings be upon him) used to supplicate, he would turn the inner part of his palms towards his face.
Hadith Referenceمسند احمد / مسند المدنيين رضي الله عنهم اجمعين / 16563
Hadith Gradingحکم دارالسلام:إسناده ضعيف لضعف ابن لهيعة، وقد اختلف عليه فيه إسناداً ومتناً، وخلاد بن السائب مختلف فى صحبته