I heard the Messenger of Allah ﷺ say, "When one of you performs ablution thoroughly and then sets out heading for the prayer, let him not interlace his fingers, for he is already in prayer."
حدثنا إسماعيل بن عمر حدثنا داود بن قيس عن سعد بن إسحاق بن فلان بن كعب بن عجرة أن أبا ثمامة الحناط حدثه أن
سمعت رسول الله ﷺ يقول إذا توضأ أحدكم فأحسن وضوءه ثم خرج عامدا إلى الصلاة فلا يشبك بين يديه فإنه في الصلاة
Its chain of transmission is hasan, because of Abu Thamama al-Hannat, whom Ibn Hibban rated as trustworthy while Daraqutni considered him unknown. It is only rated hasan because many others corroborate the hadith on this point. It was narrated by Abu Dawud (1/154, no. 562) and Tirmidhi (2/228, no. 386) from a man from Kaab, by Malik (1/33, no. 33), by Tayalisi (no. 1063), by Ibn Hibban (5/382, no. 2036, Ihsan), and by Ibn Khuzayma (no. 439). Hakim graded it sahih (1/206), and Dhahabi agreed with him, but by another route from Abu Hurairah.