when something good came their way they said this is ours. and when something bad happened to them they ascribed the evil omen to moses and those with him. in fact their omen is with god but most of them do not know.
فإذا جاءتهم الحسنة قالوا لنا هذه وإن تصبهم سيئة يطيروا بموسى ومن معه ألا إنما طائرهم عند الله ولكن أكثرهم لا يعلمون