2 Kings 2:17

And they press upon him, till he is ashamed, and he saith, 'Send ye;' and they send fifty men, and they seek three days, and have not found him;

2 Kings 8:11

And he setteth his face, yea, he setteth it till he is ashamed, and the man of God weepeth.

2 Samuel 18:22-23

And Ahimaaz son of Zadok addeth again, and saith unto Joab, 'And whatever it be, let me run, I pray thee, I also, after the Cushite.' And Joab saith, 'Why is this -- thou art running, my son, and for thee there are no tidings found?' --

Luke 11:8

'I say to you, even if he will not give to him, having risen, because of his being his friend, yet because of his importunity, having risen, he will give him as many as he doth need;

Romans 10:2

for I bear them testimony that they have a zeal of God, but not according to knowledge,

Hebrews 11:5

By faith Enoch was translated -- not to see death, and was not found, because God did translate him; for before his translation he had been testified to -- that he had pleased God well,

Treasury of Scripture Knowledge

Summary

And when they urged him till he was ashamed, he said, Send. They sent therefore fifty men; and they sought three days, but found him not.

Found him not

Bible References

They urged

2 Samuel 18:22
And Ahimaaz son of Zadok addeth again, and saith unto Joab, 'And whatever it be, let me run, I pray thee, I also, after the Cushite.' And Joab saith, 'Why is this -- thou art running, my son, and for thee there are no tidings found?' --
Luke 11:8
'I say to you, even if he will not give to him, having risen, because of his being his friend, yet because of his importunity, having risen, he will give him as many as he doth need;
Romans 10:2
for I bear them testimony that they have a zeal of God, but not according to knowledge,

Found him not

Hebrews 11:5
By faith Enoch was translated -- not to see death, and was not found, because God did translate him; for before his translation he had been testified to -- that he had pleased God well,