3:5 born of water and the Spirit. Some suggest that the “water” is the release of fluid that accompanies physical birth, but linguistic considerations point to understanding “water” and “Spirit” as referring to a single spiritual birth. Many interpreters understand “water” here as the water of baptism, but such a reference, before Christian baptism was instituted, would have been meaningless to Nicodemus. Others find a reference to John’s baptism, but Jesus nowhere makes John’s baptism a requirement for salvation. Probably the statement refers to Old Testament passages in which the terms “water” and “Spirit” are linked to express the pouring out of God’s Spirit in the end times (Is. 32:15; 44:3; Ezek. 36:25–27). The presence of such rich Old Testament imagery accounts for Jesus’ reproof of Nicodemus (v. 10): as a “teacher of Israel,” he should have understood.