It is famously said that Yom Kippur, also known as Yom Kippurim, can be read Yom k’Purim – the day that is like Purim. In this vein, Yom Kippur is only a reflection of what Purim is. It would also be evident that if Yom Kippur is about atonement and teshuva, then Purim would be too, albeit in different manners on the respective days.
All year round, we are meant to give charity, but on Purim, there is a more particular emphasis than usual, so much so that the Rambam codifies it as כל הפושט ידו נותנים לו – whoever holds out his hand, give him.
There are people who say that Purim is therefore a highly auspicious time to pray, as if we reach out to Hashem – פושט ידו – then Hashem will be compelled to respond – נותנים לו.
R’ Yosef Kaplan explains this differently.
We say of Hashem that His יד is פושט to us – His hand is extended to welcome back people who do teshuva. The Halacha on Purim is כל הפושט ידו נותנים לו – if Hashem’s hand is out, how could we not give Him what He seeks, that we return to Him?