What are the signs that a supplication has been answered, and how is the hour of acceptance on Friday known?

There are no legal signs indicating the acceptance of a supplication, but some scholars have mentioned empirical signs for it, such as: awe, weeping, goosebumps, trembling, and fainting, followed by the heart becoming tranquil, the spirit becoming calm, and a sense of relief, as if the supplicant was carrying a heavy burden that was then lifted from him.

Nevertheless, the Shari'ah requires the servant to supplicate with certainty of acceptance and presence of heart, as evidenced by the Prophet's (peace and blessings be upon him) saying: "Supplicate to Allah while you are certain of being answered, and know that Allah does not answer a supplication from a heedless, inattentive heart."