1 Corinthians 9:17

For if I preached because [I personally decided] I wanted to, I could claim a reward. But if I did not preach from a personal decision to do so, then it would be because I was entrusted with the task [by God].

2 Corinthians 8:12

For if the eagerness is there, [then] whatever a person has [to give] is acceptable, and not what he does not have.

2 Corinthians 9:7

Each person should give what he has decided to in his heart, not grudgingly, nor out of a feeling that he has to, for God loves a cheerful giver.

Philippians 2:13

for it is God who is at work in you, both to motivate the desire and to carry out what pleases Him.

Revelation 16:5-6

Then I heard the angel [in charge] of the waters saying, "You are just, [you] who are [in the present] and who were [in the past], O Holy One, because you have judged [that these things should happen].

Revelation 18:20

Be glad, heaven, and you saints, and you apostles, and you prophets, for God has brought judgment on her for you [i.e., for the way she treated you].'"

Revelation 19:2

For His judgments are true and just; He has judged [i.e., condemned] the great prostitute who corrupted the earth with her sexual immorality, and He has punished her for [shedding] the blood of His servants."

Treasury of Scripture Knowledge

Summary

Praise ye the LORD for the avenging of Israel, when the people willingly offered themselves.

Bible References

For the avenging

Revelation 16:5
Then I heard the angel [in charge] of the waters saying, "You are just, [you] who are [in the present] and who were [in the past], O Holy One, because you have judged [that these things should happen].
Revelation 18:20
Be glad, heaven, and you saints, and you apostles, and you prophets, for God has brought judgment on her for you [i.e., for the way she treated you].'"
Revelation 19:2
For His judgments are true and just; He has judged [i.e., condemned] the great prostitute who corrupted the earth with her sexual immorality, and He has punished her for [shedding] the blood of His servants."

When

1 Corinthians 9:17
For if I preached because [I personally decided] I wanted to, I could claim a reward. But if I did not preach from a personal decision to do so, then it would be because I was entrusted with the task [by God].
2 Corinthians 8:12
For if the eagerness is there, [then] whatever a person has [to give] is acceptable, and not what he does not have.
2 Corinthians 9:7
Each person should give what he has decided to in his heart, not grudgingly, nor out of a feeling that he has to, for God loves a cheerful giver.
Philippians 2:13
for it is God who is at work in you, both to motivate the desire and to carry out what pleases Him.
Philemon 1:14
But I did not want to do anything without your permission, so that your goodness [of heart] would not be shown out of a feeling of obligation, but out of willingness.