A hadith and commentary.
It is recorded in the two Sahih collections that Dimam Ibn Tha'laba said to the Prophet, peace and blessings of Allah be upon him, "I adjure you by Allah."
"Did Allah command you to do such and such?"
The commentary:
Al-Baghawi stated in his beneficial book, Sharh al-Sunnah, that "I adjure you by Allah" means "I ask you by Allah."
The meaning is: "I ask you by Allah, raising my nashid," that is, my voice; for nashid refers to raising one's voice, and from this comes the recitation of poetry, which is the act of raising one's voice with it.