What is the best explanation of first four lines this poem let you not to marriage true minds?

Please provide the poem you're referring to so I can give you the best explanation of the first four lines.

For example, you could say:

"Please explain the first four lines of this poem:

Let me not to the marriage of true minds

Admit impediments. Love is not love

Which alters when it alteration finds,

Or bends with the remover to remove."

Once you provide the poem, I can help you understand those opening lines.