What is the ruling on uttering a few words, unintelligible and inaudible to others, during prayer?

"Whoever speaks in their prayer intentionally and knowing of its prohibition, and not for the benefit of the prayer, their prayer is invalidated by consensus. As for speaking for the benefit of the prayer, the correct view is that it does not invalidate it if the intent of the tasbih (glorification) was not understood and it was limited to what was necessary, based on the hadith of Dhul-Yadain. And whoever speaks out of forgetfulness and their speech is not prolonged, their prayer is not invalidated according to the majority of scholars. Likewise, whoever speaks out of ignorance of the ruling, the correct view is that their prayer is not invalidated."