The Ruling on Abandoning a Wife For a Long Time
Question :
What is the answer in the Islamic Law and in truth to one who abandons his wife for a year or more than that for the purpose of working, in order to provide for his family what they need in order to live. Bear in mind that there are others whose absence is not for this reason alone, rather, they build palaces with it, and buy buses and other such trappings of the life of this world? And there is no doubt that this prolonged absence is one of the causes of adultery, either committed by the men or by the women. We ask Allah for guidance and success.
Answer:
If the husband and wife agree to this absence whether it is long or short-accompanied by chastity, then there is no sin upon them. If one of them fears for him or herself due to the absence which is necessary in order to earn a living, he should ask his partner for his right, by which a meeting is achieved, in order to preserve honor and to maintain chastity and protect the private parts (from illegal sexual intercourse).
If he refuses, the one in need should submit the matter to a Judge in order to judge between them by what Allah has legislated, bearing in mind that it is not necessarily so that one whose wife is not with him, or one whose husband is not with her, will commit adultery even if the period of time is protracted. And may peace and blessings be upon our Prophet, Muhammad and upon his family and Companions.
Source:
The Permanent Committee
Fatawa Islamiyah, Vol. 5 Pages 394-395