It states in Devarim 1:3,5,”It was in the fortieth year, on the eleventh month, on the first of the month (Rosh Chodesh Shevat)… Moshe began explaining the Torah…” Tzaddikim said that this teaches us that on Rosh Chodesh Shevat, new bounties of Torah come down, to help people understand Torah. Moshe’s explaining the Torah, brought clarity in Torah for all generations.
The Chidushei HaRim zt’l would say that on Rosh Chodesh Shevat, the wellsprings of Torah open. The chiddushei Torah of the entire year – for every Torah student – comes from Rosh Chodesh Shevat. The Avnei Nezer zt’l (and some say the Chidushei HaRim zt’l) said he can tell the difference between his chiddushei Torah before Rosh Chodesh Shevat and the chiddushei Torah learned after Rosh Chodesh Shevat.
Rosh Chodesh Shevat is therefore an ideal time to make a new commitment towards
studying and growing in Torah. ~ R’ Elimelech Biderman Shlita