Sayyiduna Ibn Abbas (may Allah be pleased with them both) said regarding the statement of Allah, the Mighty and Majestic: “And not a leaf falls but that He knows it”: There is no tree on land or sea except that there is an angel appointed over it who writes down every leaf that falls from it.
Hadith Referenceسنن سعید بن منصور / كتاب التفسير / 881