Jamieson, Fausset and Brown on Song of Solomon 2:3

3. Her reply. apple--generic including the golden citron, pomegranate, and orange apple (Pr 25:11). He combines the shadow and fragrance of the citron with the sweetness of the orange and pomegranate fruit. The foliage is perpetual; throughout the year a succession of blossoms, fruit, and perfume (Jas 1:17).

among the sons--parallel to "among the daughters" (So 2:2). He alone is ever fruitful among the fruitless wild trees (Psa 89:6; He 1:9).

I sat ... with ... delight--literally, "I eagerly desired and sat" (Psa 94:19; Mr 6:31; Ep 2:6; 1Pe 1:8).

shadow--(Psa 121:5; Is 4:6; 25:4; 32:2). Jesus Christ interposes the shadow of His cross between the blazing rays of justice and us sinners.

fruit--Faith plucks it (Pr 3:18). Man lost the tree of life (Ge 3:22, 23). Jesus Christ regained it for him; he eats it partly now (Psa 119:103; Joh 6:55, 57; 1Pe 2:3); fully hereafter (Re 2:7; 22:2, 14); not earned by the sweat of his brow, or by his righteousness (Ro 10:1-21). Contrast the worldling's fruit (De 32:32; Lu 15:16).