Tehillim is Good for Teshuva:
This can be explained by quoting the words of Sefer Agra D’Kallah, which state that the exile in Mitzrayim was “a golus that incorporated all other exiles.” Therefore, although the pasuk is speaking about the golus in Egypt, it is hinting to all other exiles and saying how to be redeemed from them all.
It is known that the redemption from all exiles depends on Torah and teshuvah. Teshuva is something every individual can do, but not everyone can learn Torah on the level of a talmid chochom. However, Hashem promised Dovid Hamelech that reciting his Sefer Tehillim would be considered like learning Nega’im and Ohalos. This means that when a Yid says Tehillim, it is considered like he learned Torah and did teshuva. This is hinted to in the words “shemos bnei Yisroel haba’im Mitzrayma”, which contain a reference to both Tehillim and teshuva.
