John Wesley on Isaiah 1:1

Vision - Or, the visions; the word being here collectively used: the sense is, this is the book of the visions or prophecies. As prophets were called Seers, 1Sam 9:9, so prophecies are called visions, because they were as clearly and certainly represented to the prophets minds, as bodily objects are to mens eyes. Saw - Foresaw and foretold. But he speaks, after the manner of the prophets, of things to come, as if they were either past or present. Judah - Principally, but not exclusively. For he prophecies also concerning Egypt and Babylon, and divers other countries; yet with respect to Judah. The days - ln the time of their reign. Whence it may be gathered, that Isaiah exercised his prophetical office above fifty years altogether.