Where is “Al-Aqsa”?

Salam Al-Hannat reported that a man asked Imam As-Sadiq (a.): “What are the excellent places for prostration (Masjid)?” He said: “The sacred place for prostration (Al-Masjid-ul-Haram) and the place for prostration of the Messenger (Masjid-ur-Rasul).” I said: “What about the furthest place of prostration (Al-Masjid-ul-Aqsa)?” He said: “The one to whom the messenger of God (s.) was sent to travel by night is in the heaven.” I said: “The people say that it is about Jerusalem (Bait-ul-Maqdis).” He said: “The place of prostration in Kufah (Masjid-ul-Kufah) is more excellent than it.” [Tafsir-ul-Ayyashi, volume 2 page 279 Hadith 13]

عن سلام الحناط عن رجل عن أبي عبد الله عليه السلام قال: سألته عن المساجد التي لها الفضل فقال: المسجد الحرام ومسجد الرسول قلت: والمسجد الأقصى جعلت فداك؟ فقال: ذاك في السماء إليه اسري رسول الله صلى الله عليه وآله فقلت: إن الناس يقولون انه بيت المقدس؟ فقال: مسجد الكوفة أفضل منه

Muhammad Ibn Murtada reported that Ali Ibn Ibrahim said: “Muhammad Al-Baqir (a.) sat in the sacred place of prostration (Al-Masjid-ul-Haram) and looked once to heaven and once to Ka’bah. Then he said: “Praise be to Him Who made His servant travel by night from the sacred to the most distant place of prostration.” (17:1) And he repeated it three times. Then he turned to Isma’il Al-Ju’fii and said: “O Iraqis, what do the people of Iraq say about this verse?” He said: “They say that He made him travel from the sacred place of prostration (Al-Masjid-ul-Haram) to Jerusalem (Bait-ul-Maqdis).” He said: “It is not true, what they are saying, but He made him travel from here to there. And he pointed his hand to the heaven and said: “What is between the two is sacred.” [As-Safi Fi Tafsir Kalamillahi l-Wafi, Volume 3, page 166]

عن محمد بن مرتضى الكاشاني عن علي بن إبراهيم القمي عن أبي جعفر الباقر عليه السلام أنه كان جالسا في المسجد الحرام فنظر إلى السماء مرة وإلى الكعبة مرة ثم قال سبحان الذي أسرى بعبده ليلا من المسجد الحرام إلى المسجد الأقصى وكرر ذلك ثلاث مرات ثم التفت إلى اسماعيل الجعفي فقال أي شيء يقولون أهل العراق في هذه الآية يا عراقي قال يقولون أسرى به من المسجد الحرام إلى بيت المقدس فقال ليس كما يقولون ولكنه أسرى به من هذه إلى هذه وأشار بيده إلى السماء وقال ما بينهما حرم