Moses and the Israelites received the Law on the fiery mount. Israel was bound to it by covenant and its violation meant judgement upon them. This Law governed all aspects of life from agricultural to sexual policy and marked the people as God’s own. But the Law itself and the prophets too understood that the Law itself would one day be transcended (Rom 3.21).
The Church received the Spirit in the fiery upper room. She was bound together by another covenant; and it was a covenant that has no Law but Judgement. The Feast celebrated the giving of Torah, but in Jerusalem was given no new law, rather unfettered possibility of human and divine reconciliation under the one Lord in one Spirit. John 20.19-23 means the book of Acts. To bind and loose, to forgive and retain, these are not self-grounded proclamations of a new authoritative community – No! There is no authority handed over to the Church to make a new Law; rather Judgement is the necessary way of living beyond the Law, and all judgements are provisional as even the apostolic ‘Council of Jerusalem’ is. The Spirit blows now where She wills and perpetually gives Judgement, which the Church tries to discern. The Spirit can fall before baptism; She can proclaim clean what was formerly unclean.
The Spirit is not bound by any Law whatsoever.