I will not sacrifice to the Lord my God burnt offerings that cost me nothing.

2 Samuel  24:15-25
So the Lord sent a plague on Israel from that morning until the end of the time designated, and seventy thousand of the people from Dan to Beersheba died. When the angel stretched out his hand to destroy Jerusalem, the Lord relented concerning the disaster and said to the angel who was afflicting the people, “Enough! Withdraw your hand.” The angel of the Lord was then at the threshing floor of Araunah the Jebusite.
On that day Gad went to David and said to him, “Go up and build an altar to the Lord on the threshing floor of Araunah the Jebusite.” So David went up, as the Lord had commanded through Gad.
But the king replied to Araunah, “No, I insist on paying you for it. I will not sacrifice to the Lord my God burnt offerings that cost me nothing.”
So David bought the threshing floor and the oxen and paid fifty shekels of silver for them. David built an altar to the Lord there and sacrificed burnt offerings and fellowship offerings. Then the Lord answered his prayer in behalf of the land, and the plague on Israel was stopped.
The first readers did not need to be told the tremendous significance of David's purchase, explicitly mentioned in 1 Chronicle. On this threshing-floor the Temple was built, close to the place where Abraham prepared to offer up Isaac.
Why?
When God sends disaster or punishment to men, it is a severe punishment. One day there were seventy thousand of the people died. 
God who forgives David and his people in Jerusalem, so God grieved and said to the angel "Enough! Withdraw your hand."
David purchased the land and make burnt offerings. Give an offering to the Lord needs to pay, 
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後悔不是做錯了，可以改變了。憐惜眾人。
神的恩典在前面，大衛的禱告在後面。不是多麼會祈求，神的恩典早已預備。
這裏就是大衛看見天使的地方。
沒有付出代價的奉獻，不叫奉獻。我們不能把神當作資源回收場，把自己不用的奉獻給神！
不能隨便慷他人之慨！
瘟疫早已止住，不是大衛獻祭才停止。大衛並不知瘟疫已經停，而是迦德說了，就聽話。
大衛願意聽別人的諫
母耳記停在神為人預備的路。
人在恩典之下、順服、謙卑、禱告。結束在垂聽人民的禱告
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How?
H--
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H
Take our time and effort and financial support to the Lord, for pay nothing is not really offering made to the Lord. No praise to the Lord with word only but action following up.