Mishkat al-Masabih

Zaid b. Thabit and ‘A’isha said that the middle prayer is the noon prayer. Malik transmitted it from Zaid and Tirmidhi from both of them without a full isnad.

عَن زيد بن ثَابت وَعَائِشَة قَالَا: الصَّلَاةُ الْوُسْطَى صَلَاةُ الظُّهْرِ رَوَاهُ مَالِكٌ عَن زيد وَالتِّرْمِذِيّ عَنْهُمَا تَعْلِيقا