"God Willing" in Arabic.
This phrase is commonly used by Muslims to convey a sense of hope for the future. It's kinda like saying "hopefully" after you mention some event that you hope will come to pass.
I.E: "In 4 years time, I will be done with school, Insha Allah."
What's interesting about this phrase is the fact that the speaker isn't the only one who uses it; the audience is also expected to say "Insha Allah" after someone describes an event in the future that they would like to see come to pass. For example, if someone had said the above sentence whilst around me, it would be customary for me to also say "Insha Allah".
Don't leave yet though, I have a funny!
Three men were sitting on a park bench in an Arab country one day when a beautiful woman passed by. Being a good Muslim, the woman was modestly dressed according to the rules of the Quran (hair covered, closed neck, etc.).
Upon seeing the woman, the first man was pleased at her modest dress and said, "Alhumdulallah" (All praise belongs to Allah, a phrase of appreciation).
The second man was also pleased by the sight of a decently dressed, proud Muslim woman and said, "Mash Allah" (God has willed it, another phrase of appreciation.)
The third man, who was not quite as "pure of heart" as the other two, quietly whispered...
"Insha Allah".
Please refrain from laughing too hard.