Birds are divided in the Mosaic law into two classes, (1) the clean (Leviticus 1:14-17; 5:7-10; 14:4-7), which were offered in sacrifice; and (2) the unclean (Leviticus 11:13-20). When offered in sacrifice, they were not divided as other victims were (Genesis 15:10). They are mentioned also as an article of food (Deuteronomy 14:11). The art of snaring wild birds is referred to (Psalm 124:7; Proverbs 1:17; 7:23; Jeremiah 5:27). Singing birds are mentioned in Psalm 104:12; Ecclesiastes 12:4. Their timidity is alluded to (Hosea 11:11). The reference in Psalm 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."