﴿ إِذْ تَلَقَّوْنَهُۥ بِأَلْسِنَتِكُمْ وَتَقُولُونَ بِأَفْوَاهِكُم مَّا لَيْسَ لَكُم بِهِۦ عِلْمٌۭ وَتَحْسَبُونَهُۥ هَيِّنًۭا وَهُوَ عِندَ ٱللَّهِ عَظِيمٌۭ ﴾

“when you take it up with your tongues, uttering with your mouths something of which you have no knowledge, and deeming it a light matter whereas in the sight of God it is an awful thing!”

when you were receiving it welcomingly with your tongues that is to say when you were reporting it one from the other one of the two letters tā’ has been omitted from the verb tatalaqqawnahu ‘you were receiving it’; idh ‘when’ is dependent because of massakum ‘befallen you’ or afadtum ‘engaged in’ and were uttering with your mouths that whereof you had no knowledge supposing it to be a light matter a sinless act while with God it was grave in sinfulness.