وَقَالُوۡا لَنۡ نُّؤۡمِنَ لَكَ حَتّٰي تَفۡجُرَ لَنَا مِنَ الۡاَرۡضِ يَنۭۡ بُوۡعًاۙ‏

And they say, "We will not believe you until you break open for us from the ground a spring