the call is over, he returns. When the call to commence prayer is given, he retreats; when it is over, he returns, coming between a man and his thoughts and saying, ‘Remember this, remember that,’ reminding him of things he had not been thinking about, until the man becomes so distracted that he no longer knows how much he has prayed.”
If the call to prayer drives Satan away, while dogs bark upon seeing devils, how can it be proper to say to the caller, “A stab and deadly poison for you!” because of his shortcoming in allowing his heart to become heedless, yet say to the dog, “At your service and ready to help!” because it glorifies Allah with praise? This is a faulty argument.
As for the heedless person, his reward is diminished by his heedlessness. Abū Dāwūd relates in his Sunan, from ʿAmmār, that the Prophet, may Allah bless him and grant him peace, said:
“A servant may finish his prayer with only half of it recorded to his credit, or a third, or a quarter, or a fifth, or a sixth”—until he said, “or a tenth.”
There is no doubt, then, that heedlessness diminishes the reward. Deserving punishment, however, is a separate matter. Even if he deserves punishment, it is not permissible for that punishment to be a response to the good deed he has outwardly performed.