ותאמר שבי בתי עד אשר תדעין איך יפל דבר כי לא ישקוט האיש כי אם כלה הדבר היום (רות ג:יח)
Boaz wasn’t sure if he would be the “go’el”, the redeemer, for Elimelech’s estate at this point. Negotiations with “Ploni Almoni” were still pending. Still, Boaz was determined to complete the process on that very day. The Chofetz Chaim used this Pasuk to encourage us to serve Hashem with “zrizut”, alacrity, or zeal.
He points out, that according to Chazal, had Boaz delayed he would have missed out on performing the Mitzva and affecting the future of Israel.
Meslilat Yesharim writes that it is known that serving Hashem is with desire of the heart and longing of the soul. Alas, that doesn’t always come easily.
In order to achieve that level of Avodat Hashem, he advises acting with “zrizut” to awaken our inner desire. At Mt Sinai we were certainly moved and motivated. Our task is to build and keep that momentum throughout our lives.