The name Al-Samad is mentioned only once in the entire Quran, in Surat Al-Ikhlas (Sincerity) 112. Below is the link to a beautiful and very thorough explanation of its meaning, significance, roots in the Arabic language, application in our lives, and more, including an answer to the question “why is this name mentioned only once in the Quran?” To which I would also add: its placement in the Quran is also expressive of its meaning, right in the center or “heart” of the Quran. (Article below by Sheikh Mohammad Elshinawy on the Yaqeen Institute website.)
114 Chambers 