It appears that you are referring to the nymph's reply to the amorous shepherd in Sir Walter Raleigh's The Nymph's Reply To The Shepherd.
Sir Walter Raleigh's poem answers Christopher Marlowe's The Passionate Shepherd To His Love, line by line. In short, the nymph turns down the shepherd's invitation to live with him and to be his lover.
In the first stanza, the nymph is of the opinion that she may reconsider the shepherd's request if only there was 'truth in every shepherd's tongue.' In the second and third stanza, she equates the transience of love to the decay which eventually marks the passing of summer to winter.
When rivers rage and rocks grow cold;
The flowers do fade, and wanton fields
To wayward winter reckoning yields;
In the fourth and fifth stanzas, the nymph is of the opinion that the shepherd's material gifts will fade with time, much like the loveliness of nature. She decides to give him an ultimatum, however, telling him that if
youth last and love still breed,
Had joys no date nor age no need,
Then these delights my mind might move
To live with thee and be thy love.
In the nymph's opinion, the shepherd's suit isn't the least bit attractive to her.