The phrase fi sabilillah (في سبيل الله fī sabīli llāhi) is an Arabic expression meaning "in the cause of Allah", or more befittingly, "for the sake of Allah". Alternative spellings for fi sabilillah include fisabilillah and fisabillillah and is defined as, "One who fights for the cause of Allah" or "Jihad in the way of Allah".
The phrase is found frequently in the Qur'an, e.g. in surah 9, verse 60:
From the above context it is closely associated with almsgiving or charity, as in جعله في سبيل الله, meaning "he dedicated the revenue or profit to be used in the cause of God", i.e. "he gave to charity". A classical example discussed by Lane in his Arabic-English Lexicon of 1863 is that of Umar who decided to give the revenue of a palm grove of his to charitable use. Because of these connotations, the phrase is closely associated with the concept of zakah in fiqh (Islamic jurisprudence). The 14th-century manual Umdat al-Salik associates the phrase with jihad. In Islam, the phrase al-jihad fi sabilillah is the equivalent of the western notion of bellum justum or just war. Such a "just war" or "war in the cause of God" has been propagated in modern Islamic fundamentalism beginning in the late 19th century, and notably in the mid-20th century in Islamic revivalism.
To love someone for the sake of Allah is similar to Platonic love.