1 Thessalonians 2:9

For ye remember, brethren, our labour and toil: for night and day working hard, that we might be no burden to any of you, we preached unto you the gospel of God.

2 Thessalonians 3:8

neither did we eat bread with any man unpaid for, but with labour and toil worked night and day, that we might be burdensome to none of you:

Treasury of Scripture Knowledge

Summary

I have seen the travail, which God hath given to the sons of men to be exercised in it.

Bible References

General references

1 Thessalonians 2:9
For ye remember, brethren, our labour and toil: for night and day working hard, that we might be no burden to any of you, we preached unto you the gospel of God.
2 Thessalonians 3:8
neither did we eat bread with any man unpaid for, but with labour and toil worked night and day, that we might be burdensome to none of you: