Shuba reported,

Abdullah bin Abbas passed by Abdullah bin Harith bin Abu Rabia while he was praying with his hair braided and tied behind his head. He stopped beside him and began untying the knot of his hair. Abdullah bin Harith allowed him to do so until he had finished untying it, then sat down.When Ibn Harith finished his prayer, he came to Ibn Abbas and asked, "Why did you do what you just did to my head?"He replied, "I heard the Messenger of Allah ﷺ say, 'The one who prays with his hair tied behind his head is like one who prays with his hands bound.'"

Ahmad 2902

Sahih

حدثنا حجاج أخبرنا ليث حدثنا عمرو بن الحارث عن بكير بن عبد الله

عن شعبة مولى ابن عباس أو كريب مولى ابن عباس

أن عبد الله بن عباس مر بعبد الله بن الحارث بن أبي ربيعة وهو يصلي مضفور الرأس معقودا من ورائه فوقف عليه فلم يبرح يحل عقد رأسه فأقر له عبد الله بن الحارث حتى فرغ من حله ثم جلس فلما فرغ ابن الحارث من الصلاة أتاه فقال علام صنعت برأسي ما صنعت برأسي آنفا قال إني سمعت رسول الله ﷺ يقول مثل الذي يصلي ورأسه معقود من ورائه كمثل الذي يصلي مكتوفا

أحمد 2902صحيح
Contents
Reference
Commentary
Ayat
Collection
Musnad Ahmad
Book
Abdullah bin Abbas bin Abdul-Muttalib
Numbering
Darussalam 2902
Ahmad 2902