Here is the etymology they provided:

"Munificent" was formed back in the late 1500s when English speakers, perhaps inspired by similar words such as "magnificent," altered the ending of "munificence." "Munificence" in turn comes from "munificus," the Latin word for "generous," which itself comes from "munus," a Latin noun that is variously translated as "gift," "duty," or "service." "Munus" has done a fine service to English by giving us other terms related to service or compensation, including "municipal" and "remunerate."

This brings to mind several passages.

Matthew 7:7-11

"Ask, and it will be given to you; seek, and you will find; knock, and it will be opened to you. For everyone who asks receives, and he who seeks finds, and to him who knocks it will be opened.  Or what man is there among you who, when his son asks for a loaf, will give him a stone?  Or if he asks for a fish, he will not give him a snake, will he?  If you then, being evil, know how to give good gifts to your children, how much more will your Father who is in heaven give what is good to those who ask Him!

Here Messiah describes our Heavenly Father as munificent.  The Father gives generously to those who ask of Him.

In the story of Zaccheus (Luke 19) we find this:

Luke 19:8

Zaccheus stopped and said to the Lord, "Behold, Lord, half of my possessions I will give to the poor, and if I have defrauded anyone of anything, I will give back four times as much."

In regards to giving to the poor only a tenth is required by the Torah. (Deuteronomy 26:12)  Zaccheus gave half.

In regards to restitution for fraud only double payment is required by the Torah (Exodus 22:4, 22:7, 22:9).  Zaccheus gave four times as much as he took.

This is the abundance of repentance and blessing that comes from faith in Messiah Yeshua.  Zaccheus was munificent in his actions as a result of the faith G-d had given to him.

There is a word of prophecy in Isaiah that also speaks of G-d's munificence:

Isaiah 25:6

The LORD of hosts will prepare a lavish banquet for all peoples on this mountain; A banquet of aged wine, choice pieces with marrow, And refined, aged wine.

Glory and praise to the Lord for the promise of that day.