Abu Dawud

763. Commentary:
➊ These pure words are extremely blessed, and it is recommended (mustahabb) to recite them as praise (thana).
➋ It is apparent that this Companion (radi Allahu anhu) uttered these words in a loud voice, but for us, reciting them aloud will not be considered Sunnah, otherwise it would cause disturbance to other worshippers.

902. Commentary:

➊ The fact that he was out of breath is evidence that the Companion (radi Allahu anhu) came to the prayer rather quickly. Thus, moving with a speed less than running is permissible, provided that seriousness and dignity are maintained.

➋ Because he was out of breath, he could not control his voice, so his voice became loud and was heard by others.

➌ The mutual relationship of the Prophet (sallallahu alayhi wa sallam) with the noble Companions (radi Allahu anhum) was extremely compassionate, and he would always console and encourage his Companions on every good occasion.

Hadith Commentary: Benefits and Issues: From this hadith, Hafiz Ibn Hajar rahimahullah has deduced that it is permissible to recite remembrances (adhkar) in prayer other than those that are transmitted, provided that they are not contrary to what is transmitted. On this, Allamah Saeedi writes: This is not correct, because this remembrance was made in the presence of the Prophet sallallahu alayhi wa sallam, and he approved and permitted it; thus, its permissibility is known from the tacit approval and explanation of the Prophet sallallahu alayhi wa sallam. Now that revelation has ceased, no person has the right to add any remembrance or supplication from himself in prayer or in any specific act of worship. In fact, our jurists (fuqaha) have said that if, after the first tashahhud, someone recites (اللَّهُمَّ صَلِّ عَلَى مُحَمَّدٍ) (O Allah, send blessings upon Muhammad) either forgetfully or intentionally, then prostration of forgetfulness (sajdah sahw) will become obligatory upon him. In the Shari‘ah of the Messenger of Allah sallallahu alayhi wa sallam, later people have no right to make any addition. (Sharh Muslim: 2/212)

The question is: when it is established that revelation has ceased and the Shari‘ah is complete, and later people have no right to make any addition in the Shari‘ah, then is it not an addition to fix the celebration of Mawlid al-Nabi sallallahu alayhi wa sallam, to invent new forms of salutations (salawat), and to specify various types of supererogatory acts of worship for conveying reward (isal thawab) without any Shar‘i specification? How have all these matters become “commendable”? There is allowance for sending salutations (salat) in the first tashahhud; in fact, some Imams have even declared it obligatory, yet prostration of forgetfulness (sajdah sahw) has been prescribed for it. Similarly, if a worshipper sneezes during prayer, he may say “alhamdulillah” (all praise is due to Allah) with his tongue. However, according to one narration from Imam Abu Hanifah rahimahullah, his prayer will become invalid. So, can those matters which the followers of Imam Abu Hanifah rahimahullah have innovated after him be considered commendable in his view?