Easton's Bible Dictionary: M. G. Easton, M.A., D.D.
Of a tree. The olive-leaf mentioned Gen. 8:11. The barren fig-tree had nothing but leaves (Mt. 21:19; Mk. 11:13). The oak-leaf is mentioned Isa. 1:30, 6:13. There are numerous allusions to leaves, their flourishing, their decay, and their restoration (Lev. 26:36; Isa. 34:4; Jer. 8:13; Dan. 4:12, 14, 21; Mk. 11:13, 13:28). The fresh leaf is a symbol of prosperity (Ps. 1:3; Jer. 17:8; Ezek. 47:12); the faded, of decay (Job 13:25; Isa. 1:30, 64:6; Jer. 8:13).
Leaf of a door (1 Ki. 6:34), the valve of a folding door.
Leaf of a book (Jer. 36:23), perhaps a fold of a roll.