The Prophet ﷺ forbade a man to pray in a single garment with no part of it covering his shoulders.
وبالإسناد نهى النبي ﷺ أن يصلي الرجل في الثوب الواحد ليس على عاتقه منه شيء
Its isnad is sahih. Bukhari narrated it, 1/471, no. 359, Fath, in the Book of Prayer, chapter on praying in a single garment, and Muslim, 1/368, no. 516, similarly, and Abu Dawud, 625, and Darimi, 1/367, no. 1371, and Malik, 1/140.