Is the statement: "A man said to the Messenger of Allah, may Allah bless him and grant him peace: 'Teach me what will benefit me,' so he said: 'You must supplicate, for you do not know when it will be answered for you,'" a sound hadith?

The hadith reported by Abu Zakariya al-Kufi regarding the Prophet's (peace and blessings be upon him) recommendations and prohibitions is weak. Nevertheless, the virtue of supplication (du'a') is firmly established. The Muslim who supplicates is always victorious, for it brings one of three gifts: the hastening of the supplication's fulfillment, its storage for the hereafter, or the warding off of an equivalent evil. And Allah is most giving.