Praise be to Allah.
The scholars call this issue “the issue of settling scores”, concerning which there is a dispute among the scholars. Some of them say that it is not allowed to take what one is entitled to from a wrongdoer, and some say that it is allowed subject to the condition that he does not take more than he is entitled to and that there is no risk of being found out and punished. The latter is the correct view.
Shaykh al-Shanqeeti (may Allah have mercy on him) said:
If someone wrongs you and takes something of yours in an unlawful manner, and you cannot prove it, but you are able to do something similar to the way in which he wronged you, with no risk of being found out or punished, do you have the right to take what you are entitled to or not?
The more correct of the two scholarly opinions, and the one which seems closest to the apparent meaning of the texts and is based on the more sound analogy, is that you may take that to which you are entitled, and no more, because Allah says (interpretation of the meaning):
“then punish them with the like of that with which you were afflicted” [al-Nahl 16:126]
“Then whoever transgresses the prohibition against you, you transgress likewise against him” [al-Baqarah 2:194]
Among the scholars who were of this view are: Ibn Sireen, Ibraaheem al-Nakha’i, Sufyaan and others.
A number of scholars – including Maalik – said that this was not permitted. This is the view of Khaleel ibn Ishaaq al-Maaliki in his Mukhtasar, where he said concerning goods placed with a person for safekeeping: He does not have the right to take anything from them because that person wronged him. Those who held this view quoted as evidence the hadeeth: “Render back trusts to the one who entrusted it to you, and do not betray the one who betrays you.”
This hadeeth – even if we assume that it is saheeh – cannot be taken as evidence in this context, because the one who takes as much as he is entitled to, and no more, is not betraying the one who betrayed him, rather he is settling the score fairly with the one who wronged him.
Adwa’ al-Bayaan, 3/353
This is also the view of al-Bukhaari and al-Shaafa’i, as narrated by Abu Zar’ah al-‘Iraaqi in Tarh al-Tathreeb, 8/226. Al-Tirmidh narrated that it was the view of some of the Taabi’een, among whom he mentioned Sufyaan al-Thawri.
The hadeeth quoted by those who do not allow it is the hadeeth of Abu Hurayrah who said: The Prophet (S) said: “Render back trusts to the one who entrusted it to you, and do not betray the one who betrays you.” Narrated by al-Tirmidhi, 1264; Abu Dawood, 3535; classed as saheeh by al-Albaani in al-Silsilah al-Saheehah, 423.
So you can take what you are entitled to from this Jew who owns the workplace, provided that you do not take more than what you are entitled to, and provided that there is no risk of being found out, which may damage the image of Islam, because you cannot prove your rights to people. If he gives you what you are entitled to after that, in whole or in part, then you have to return what you took from him that is surplus to what you are entitled to.
And Allah knows best.