Seek the Lord, a Reflection on Isaiah 55:6-11

The invitation continues, "Seek the Lord, call upon him." But not just simple imperatives. Seek while he may be found. Call while he is near. Yes, God has made an everlasting covenant. Yes, all nations are invited. But, we aren't being reined in against our will. We are to seek, we are to do some calling. Moreover, we're supposed to do that seeking and calling now.

I don't know what to do with the phrases "while he may be found" and "while he is near." What's with the "whiles"? Are we under a time limit?

Or, can I let verse 7 help me here? Our return to the Lord enables us to realize the mercy and pardon. They are there waiting for us but we have to notice.

Or, should I give in to verse 8? How am I supposed to know everything; after all, the Lord is capable of thoughts and ways that are not available to us humans.