Is the Hadith: "Our Lord, and to You be praise and gratitude, abundant, good, blessed praise, filling the heavens and filling the earth and filling what is between them and filling what You wish of anything thereafter." And the Prophet, peace and blessings be upon him, said: "I saw thirty angels competing, each one of them wanting to record it for him before the other," authentic from the Messenger of Allah, peace and blessings be upon him?

The hadith speaks about the virtue of remembrance (dhikr) after straightening up from bowing (ruku'), which is the saying: "Rabbana wa lakal-hamd, hamdan kathiran tayyiban mubarakan fih" (Our Lord, and to You be all praise, abundant, good, and blessed praise). In it, the Prophet, peace and blessings be upon him, saw thirty-some angels competing as to which of them would write it first. This hadith is used to infer the virtue of this dhikr in prayer, and it is sunnah for the congregant (ma'mum) to add praise for Allah to the tahmid (saying "al-hamdu lillah"). It also indicates the permissibility for the congregant to sometimes vocalize the dhikr. As for adding the word "shukr" (thanksgiving) to "Rabbana wa lakal-hamd," it has not been reported in sound narrations. It is preferable to stick to what has been reported, but if it is said, it does no harm, because praise (hamd) includes thanksgiving (shukr).