Musannaf Ibn Abi Shaybah

Hazrat Ibn Aun says that I came to Madinah and caught one rak'ah of the 'Isha prayer. I began to wonder in my heart, what should I do now? Later, I asked Hazrat Qasim about this matter, and he said, "Did you fear that if you prayed four rak'ahs, Allah Almighty would punish you?!"