Let him kiss me with the kisses of his mouth, for your love is better than wine. ישקני מנשיקות פיהו כי טובים דודיך מיין Song of Songs 1:1 (1)
There are two aspects of divine service. One serves God because God loves us and receives our service with favor, and rewards a person according to his deeds with a great and hidden good, as in the verse, “No eye has seen but You, O God, Who act for those who trust in You” (2). And there is a higher level than this: those who love God only because God loves us; this love is complete. Even if they received no reward, God’s love would be enough, because it is the most sweet and dear thing that there is, greater than all else. This is the meaning of Let him kiss me with the kisses of his mouth – we are saying to God, let our love and kisses be only for the sake of Your kisses, for your love for us, and not for any reward. This is hinted at in Rashi’s comment, “The Community of Israel asks Let him kiss me with the kisses of his mouth, as a bridegroom kisses the bride mouth to mouth, not on the back of the hand” – not for any reward at all but for love and love only. This the meaning of For your love is better than wine – it is better to hear “I have loved you, says the Lord” (3) than to receive even the reward of the life to come [called “the wine that God has been saving for the righteous since Creation”].
1) The shift between first and second person is considered emblematic of (among other things) the difficulty in verbalizing our relation to God — grammar fails when we speak about/ to God. 2) Isaiah 64:3, the classic prooftext for reward in the world to come. 3) Malachi 1:2