for the superior dhikr (remembrance of Allah) is deemed superior because of what is intrinsically contained in it, not because of its chain of transmission. Dhikr is of three categories. The best is pure praise (thana) of Allah; next is wording initiated by the servant as an acknowledgement of what is due to Allah; finally comes the servant’s own supplication (duʿa). 1. The first category includes the first half of al-Fatihah, the formula Subhanaka-Allahumma… (Glory be to You, O Allah), and the tasbih uttered in bowing and prostration. 2. The second category includes the words Wajjhatu wajhi… ("I have turned my face …") and the formula recited in rukuʿ and sujud: Allahumma laka rakaʿtu wa-laka sajadtu… ("O Allah, to You I have bowed and to You I have prostrated …"). 3. The third category includes Allahumma baʿid bayni wa-baina khatayaya… ("O Allah, distance me from my sins …") and similar prayers in rukuʿ and sujud. For this reason some of Ahmad’s disciples ruled that every formula of praise—just like the opening invocation (istiftah)—is obligatory. Two reports exist from Ahmad on the matter; Ibn Batta and others adopted the view of obligation. The point is that employing a dhikr judged less meritorious—such as Abu Hurayrah’s opening invocation, or Wajjhatu… or Subhanaka… according to those who prefer the other—is sometimes better than clinging permanently to one formula and abandoning the rest, for the best guidance is the guidance of Muhammad ﷺ, as authenticated in the Sahih. He ﷺ certainly did not confine himself to a single opening invocation; the hadith of Abu Hurayrah proves that he occasionally opened the prayer with that formula. I add: Those who held that praising Allah—like the istiftah—is obligatory may have based themselves on the hadith of "the man who prayed incorrectly," narrated from Rifaaʿah ibn Rafiʿ: “No one’s prayer is complete until he performs ablution, placing each washing in its proper place, then says the takbir, praises Allah and extols Him, and recites whatever portion of the Quran is easy for him …” and so on.