Riyad as-Salihin, Book 16, Hadith 1428 (In-Book) ⓘ
Abu Hurairah (May Allah be pleased with him) reported: The Messenger of Allah said, "A slave becomes nearest to his Rubb when he is in prostration. So increase supplications while prostrating."[Muslim].
وعن أبي هريرة رضي الله عنه أن رسول الله صلى الله عليه وسلم قال: "أقرب ما يكون العبد من ربه وهو ساجد، فأكثروا الدعاء" ((رواه مسلم)).