“تکبر” in the Masnavi

They all said to him, 'We will risk our lives in this; we will gather our knowledge together and work as one.'

'Each one of us is a healer like Messiah for a world, and in our hands lies a balm for every pain.'

Out of arrogance, they failed to say 'If God wills'; so God showed them the helplessness of humankind.

By neglecting to say 'if God wills,' I mean a hardness of the heart, not merely the omission of the phrase itself, which may be just an accidental occurrence.