(a) It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) would sometimes, out of need, place his blessed hand on his blessed beard during the prayer.
(b) It is reported from Ibrahim (al-Nakha'i) (may Allah have mercy on him): Touch the beard once or so, and that is all.
It has also been narrated through another, weak, route, from the hadith of Abu Dharr. Abu Ahmad (Ibn Adi) (may Allah have mercy on him) said: Most of what this Isa al-Qaddah narrates is not corroborated.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 3433
Hadith Gradingمحدثین:ضعيف جدا
Hadith Takhrij«ضعيف جدا۔ اخرجه ابن عدي في الكامل 5/ 253»