A nasheed (alt nashid) is an Arabic musical chant, typically sung a cappella or accompanied by percussion instruments. 

The classical Arabic phrase "break the cross" is found in a famous Islamic hadith about Jesus, understood in Islam to be a Muslim prophet who will return to the earth as a cross-destroying enforcer of Islamic Sharia law.

Narrated Abu Huraira: "Allah's Apostle said, 'By Him in Whose Hands my soul is, surely [Jesus,] the son of Mary will soon descend amongst you and will judge mankind justly [as a Just Ruler]; he will break the cross and kill the pigs and there will be no jizya..."

Sahih al-Bukhari 4:60:3448.

The term "jizya" is a tax extracted from non-Muslims. In the context above, there will be no "jizya" as non Muslims will all be forced to convert to Islam or be killed.

This video has been released across most major social media platforms including encrypted Islamic State Telegram channels.

The major takeaway from Islamic State videos and other propaganda is that despite withering battlefield losses in Syria and Iraq, the threat posed by radical Islam has not abated. The tempo of attacks will ebb and flow, but the threat remains.