Sayyiduna Abdullah bin Amr (may Allah be pleased with him) relates: I saw the Prophet (peace and blessings be upon him) counting the verses in the prayer.
Al-Tabarani recorded it; its chain contains Nasr bin Tarif, who is matruk (abandoned).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2672