Before putting pen to paper

Reference: Siyar A’laam an-Nubalaa – Volume 12, Page 391

Muhammad ibn Ismaa’eel al-Bukhaaree said:

I did not put [pen to paper and record] any hadeeth in my book “Saheeh [al-Bukhaaree]” except that I washed before [doing so], and then prayed two rak’ahs.