Khalid bin Ilyas, who is also called Iyas, and he is a weak narrator, narrated from Salih, the freed slave of al-Taw'amah, from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that he said: "The Messenger of Allah (peace and blessings be upon him) used to rise in prayer on the balls of his feet."
And this is part of a hadith.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / Q2763