Morning dew
Small droplets of water on grass at dawn — moisture arriving from the air without a rain having fallen.
Morning dew in a dream is the dream's image of moisture arriving from the air without any rain having fallen. The grass is wet; nothing visible came down. The dream brings the dew when something in your life — a small grace, a piece of unexpected freshness, a kindness offered without announcement — has appeared on the surface of an ordinary morning. Dew noticed and walked in is the dream affirming the small invisible arrival. Dew dismissed as nothing, the moisture evaporating before anyone registers it, is the dream noting that the small ungifted gift was real and went unwitnessed, and the day will not get a second offering of it.