The 3rd of Sivan is the first day of the Feast of the Ascension which culminates in Pentecost. Relevant passages include:
Exodus 19 & 20
Mark 16:19-20
Luke 24:50-53
Acts 1 & 2
1 Corinthians 15:6
Please watch this video for details:
https://www.youtube.com/live/5tSMz3gaFpc
It is good practice to do Tahorat on the 3rd day of the 3rd Hebrew month dress in white and preserve your taharat until the Feast of Shavuot.
ASCENSION (MK, LK)
SAUL (LK, PL)
Then His Word and Name appeared to Saul of Tarsus.