Silsilah as-Sahihah 296 — Maximum number of fasts; Prophet's concern

Sayyiduna Abdullah bin Amr (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings be upon him) said to me: "O Abdullah bin Amr! You fast all the time and stand in prayer all night. If you continue with these deeds, your eyes will sink and you will become weak and frail. (Remember that) the person who fasts continuously has not really fasted. Do it like this: fast three days every month; this is equal to fasting the whole month." I said: I have strength for more than this. The Prophet (peace and blessings be upon him) said: "Then observe the fast of Dawud (peace be upon him); he would fast one day and break the fast the next day, and when (he faced the enemy) he would not flee."

It is narrated from Sayyiduna Salman (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "On the Day of Resurrection, a man will come who will hope to be saved on the basis of his good deeds. Those whom he wronged will come and keep taking his good deeds, until his good deeds are finished. Then another oppressed person will come, and now his own good deeds have already ended, so the bad deeds of the oppressed will be placed in his account."