Inshallah

Inshallah (Arabic: إِنْ شَاءَ ٱللَّٰهُ) is an Arabic phrase that means "if God is willing". It is used by Arabic speakers to talk about events they hope will happen.
In many religions, such as Islam, it is believed that things do not happen unless Allah (God in Arabic) lets them happen. Therefore this phrase is a hope that God will let the event happen.
"Inshallah" can also be used for sarcasm. When a person says "inshallah" in this case, it means that something will never happen.
"Inshallah" is also used in many other languages, especially where there are many Muslims or where people were introduced to the Arabic language.