Quoting Commentary for Song of Songs 2:5

“And the sons of Aaron the priests shall put fire.” Even though fire descends from heaven, it is a commandment to bring [fire] from ordinary sources in order to mix the fire from above with the fire from below, and to judge the sinner in two courts of law, in order to atone for thoughts about the type of sin that should be judged in the heavenly court, and for thoughts about the type of sin that should be judged in the earthly court. This is the reason for Sustain me with raisin cakes [ashishot] (Song of Songs 2:5) — two types of fire [esh] — for I am sick with love — these are the sins, the sickness of the soul that affects the love of the Holy One, blessed be He, and He is healed through these two fires.

Similarly, tradition imparts that the following figure the glory of the shekhinah: “like the apple among the forest’s trees” [Cant. 2:3]; “your breath is like apples’ fragrance” [Cant. 7:9]; “refresh me with apples” [Cant. 2:5]; and “under the apple tree I aroused you” [Cant. 8:5]. This figure derives from the change of the apple’s cover from green to red to white, like the appearance of the rainbow within the cloud.²³ Ezek. 1:28. The apple also figures the two cherubim, as it states in the tractate Shabbat: “‘Like the scent of a field blessed by God’ [Gen. 27:27]. R. Yehudah states in the name of Rav: ‘Like the scent of a field of apple trees.’”²⁴ b. Ta ‘anit 29b.