1QS 3
Community RuleFor it is through the spirit of true counsel concerning the ways of man that all his sins shall be expiated, that he may contemplate the light of life. He shall be cleansed from all his sins by the spirit of holiness uniting him to His truth, and his iniquity shall be expiated by the spirit of uprightness and humility. And when his flesh is sprinkled with purifying water and sanctified by cleansing water, it shall be made clean by the humble submission of his soul to all the precepts of God. Let him then order his steps {to walk} perfectly in all the ways commanded by God concerning the times appointed for him, straying neither to the right nor to the left and transgressing none of His words, and he shall be accepted by virtue of a pleasing atonement before God and it shall be to him a Covenant of the everlasting Community.
Acts 19:4
2 and said to them, “Did you receive the Holy Spirit when you believed?” They replied, “No, we have not even heard that there is a Holy Spirit.” 3 So Paul said, “Into what then were you baptized?” “Into John’s baptism,” they replied. 4 Paul said, “John baptized with a baptism of repentance, telling the people to believe in the one who was to come after him, that is, in Jesus.” 5 When they heard this, they were baptized in the name of the Lord Jesus, 6 and when Paul placed his hands on them, the Holy Spirit came upon them, and they began to speak in tongues and to prophesy.
Notes and References
"... With the discovery of the Scrolls, however, things began to change, and since 1948 many scholars have linked John directly or indirectly with the Qumran sect. The strong form of this claim - which this study shares - is that John started out as a member of the Qumran community. This is a controversial assertion, and it is based on circumstantial evidence, but there is a lot of that, including the following ... the water rites practiced by the Baptist and by the Qumran sect had a similar meaning, including their connection with repentance and forgiveness of sins (Mark 1:4; 1QS 3:4–12). Elsewhere in ancient Judaism, washing ceremonies were not connected with repentance and atonement but with the recovery of ritual purity ..."
Marcus, Joel John the Baptist in History and Theology (p. 28) The University of South Carolina Press, 2018