Bukhari

Hadith Commentary:
A person is deceived only once, thereafter he remains cautious.
It has been rightly said:
A man is shaped after enduring countless setbacks;
Henna reveals its color only after being ground upon a stone.

Hadith Commentary:
(1)
An experienced and astute Muslim becomes alert after being deceived once, but a heedless Muslim continues to be deceived repeatedly. The Messenger of Allah (sallallahu alayhi wa sallam) used these words on the occasion when Abu ‘Azza Jumahi was taken captive by the Muslims in the Battle of Badr. He mentioned his family and poverty before the Messenger of Allah (sallallahu alayhi wa sallam). The Prophet (sallallahu alayhi wa sallam), showing kindness, released him without ransom. However, he later came to fight against the Muslims in the Battle of Uhud, and the Muslims captured him again. He once more presented excuses, upon which the Messenger of Allah (sallallahu alayhi wa sallam) said:
“You cannot go to Makkah now.
A believer is not bitten from the same hole twice.”
After this, he (sallallahu alayhi wa sallam) ordered him to be killed.
(Fath al-Bari: 10/651)

Hadith Commentary: Benefits and Issues: The wording of the hadith is in the form of a report, but in terms of meaning and understanding, it is an instruction and guidance that a believer should remain alert, vigilant, and cautious. One should not live a life of heedlessness and unawareness, for due to heedlessness and unawareness, he may be deceived repeatedly.

Benefits and Issues:
To test someone who has already been tested is a very grave mistake.