Jamieson, Fausset and Brown on 1 Corinthians 10:4

4. drink--(Ex 17:6). In Nu 20:8, "the beasts" also are mentioned as having drunk. The literal water typified "spiritual drink," and is therefore so called.

spiritual Rock that followed them--rather, "accompanied them." Not the literal rock (or its water) "followed" them, as Alford explains, as if Paul sanctioned the Jews' tradition (Rabbi Solomon on Nu 20:2) that the rock itself, or at least the stream from it, followed the Israelites from place to place (compare De 9:21). But Christ, the "Spiritual Rock" (Psa 78:20, 35; De 32:4, 15, 18, 30, 31, 37; Is 28:16; 1Pe 2:6), accompanied them (Ex 33:15). "Followed" implies His attending on them to minister to them; thus, though mostly going before them, He, when occasion required it, followed "behind" (Ex 14:19). He satisfied all alike as to their bodily thirst whenever they needed it; as on three occasions is expressly recorded (Ex 15:24, 25; 17:6; Nu 20:8); and this drink for the body symbolized the spiritual drink from the Spiritual Rock (compare Joh 4:13, 14; see on 1Co 10:3).