Mount Sinai is the mountain where Allah (swt) talked to Mousa (pbuh).

سِينِينَ (Sinai): The sacred of the perfect because it is full of fruitful trees. Some interpreters considered it the erea or the place of the mountain. It is mentioned in another Surah as:

{ وَشَجَرَةً تَخْرُجُ مِن طُورِ سَيْنَاءَ تَنبُتُ بِالدُّهْنِ وَصِبْغٍ لِّلْآكِلِينَ }

(And [We brought forth] a tree issuing from Mount Sinai which produces oil and food for those who eat.) (Al-Muminoon: 20)