The heat remains in the sun until evening, then at night, it descends into my wine.

This couplet beautifully contrasts the day's warmth with the evening's comfort. It says that the heat residing in the sun until evening eventually descends into the poet's wine at night. This isn't literal heat, but a poetic expression. It suggests that the vibrancy and warmth experienced during the day, symbolized by the sun, transforms into a different kind of warmth or solace found in a drink as night falls. It speaks to finding comfort, perhaps even a gentle intoxication, as a natural progression from the day's energy to the evening's relaxation. The poet finds the day's lingering energy and passion reflected in his nightly indulgence.