The Prophet ﷺ said: “The most beloved of your names to Allah are ʿAbd Allah and ʿAbd al-Rahman” (Muslim 2132), and scholars add to them all names formed on a name of Allah. The name al-Samiʿ occurs 45 times in the Quran; its page in the 99 Names section gives its meaning and verses.
ʿAbd al-Samiʿ joins ʿabd with al-Samiʿ, from the root s-m-ʿ of hearing: the One who hears everything, whispered supplications as well as secret thoughts, and who answers. Muslims recall it in every prayer when rising from bowing: samiʿa Allahu li-man hamidah, “Allah hears the one who praises Him”.
And [mention] when Abraham was raising the foundations of the House and [with him] Ishmael, [saying], "Our Lord, accept [this] from us. Indeed, You are the Hearing, the Knowing.
So if they believe in the same as you believe in, then they have been [rightly] guided; but if they turn away, they are only in dissension, and Allāh will be sufficient for you against them. And He is the Hearing, the Knowing.