Birds are divided in the Mosaic law into two classes, (1) the
clean (Lev. 1:14-17; 5:7-10; 14:4-7), which were offered in
sacrifice; and (2) the unclean (Lev. 11:13-20). When offered in
sacrifice, they were not divided as other victims were (Gen.
15:10). They are mentioned also as an article of food (Deut.
14:11). The art of snaring wild birds is referred to (Ps. 124:7;
Prov. 1:17; 7:23; Jer. 5:27). Singing birds are mentioned in Ps.
104:12; Eccl. 12:4. Their timidity is alluded to (Hos. 11:11).
The reference in Ps. 84:3 to the swallow and the sparrow may be
only a comparison equivalent to, "What her house is to the
sparrow, and her nest to the swallow, that thine altars are to
my soul."