Passage
Wherefore do ye spend money for that which is not bread? and your labour for that which satisfieth not? hearken diligently unto me, and eat ye that which is good, and let your soul delight itself in fatness.
Isaiah 55:2 (KJV)
Nearby Context
Isaiah 55:1 Ho, every one that thirsteth, come ye to the waters, and he that hath no money; come ye, buy, and eat; yea, come, buy wine and milk without money and without price.
Isaiah 55:2 Wherefore do ye spend money for that which is not bread? and your labour for that which satisfieth not? hearken diligently unto me, and eat ye that which is good, and let your soul delight itself in fatness.
Isaiah 55:3 Incline your ear, and come unto me: hear, and your soul shall live; and I will make an everlasting covenant with you, even the sure mercies of David.
Isaiah 55:4 Behold, I have given him for a witness to the people, a leader and commander to the people.
Study Lenses
The verse centers on "light", "wherefore", "spend", "money", "bread", "labour", "satisfieth", and "hearken". It is saying that the verse draws attention to "light" and "wherefore", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 1's "Ho every one that thirsteth come ye..." into verse 3's "Incline your ear and come unto me...", so "light" and "wherefore" belong inside that flow. In Isaiah context, the local focus is the Holy One of Israel, judgment and restoration, the servant of the LORD, and Zion's hope.
A plain takeaway is to answer the verse's own emphasis on "light" and "wherefore" with trust shaped by these words, not by a vague optimism outside the passage.