When the Saviour reached the age of thirty, designing now to bring about the actual work of salvation, He first acted, then taught. Starting with the first sacrament, the foundation of all virtues, He wished to be baptized by John so as to give an example of perfect justification, and as if to impart to water, through the touch of His most pure flesh, the power of regeneration.
It is for you also to remain faithfully by His side. Once regenerated in Him, delve into His secrets, so that "on the banks of the River Jordan you may know the Father in the Voice, the Son in the Flesh, and the Holy Spirit in the Dove, and the heaven of the Trinity being open to you," you may be carried up to God.
[Bonaventure, The Works of Bonaventure I: Mystical Opuscula, José de Vinck, tr., Martino Publishing (Mansfield Centre, CT: 2016), pp. 109-110.]
The quotation is from Anselm's Meditations; the Meditations are certainly based on work by Anselm, but people seem also to have added to the work in the course of using them devotionally, so we don't know for sure what in the Meditations is definitely from Anselm and what is not.