Some sayings of Raabi’ah al-‘Adawiyyah

She once said “I seek forgiveness from Allaah for the lack of my sincerity when I say, I seek the forgiveness of Allaah.”

A man once went to Raabi'ah bint Isma'il al-'Adawiyyah, who was known by the titles, 'Mother of Goodness,' and, 'The Famous Worshipper.' He said, 'Indeed, I have perpetrated a great number of sins. If I repent, do you think that Allah will accept my repentence?"
She said, "Woe unto you! Do you not see that He invites those who turn away from Him; then why wouldn't He accept the repentance of those who turn towards Him?"

Raabi’ah al-‘Adawiyyah once said to Sufyaan al-Thawri: “You are only a few days, and when one day passes a part of you has gone. Soon, when a part of you have gone all of you will have gone. You know about this, so act upon it.”

‘Abdah bint Abi Shawwaal, who was one of the best female slaves of Allaah and who used to serve Raabi’ah, said: “Raabi’ah used to pray all night long, and just before dawn, she would take a short nap until dawn came. When she awoke with a start, I would hear her say in a terrified manner, ‘O my soul, how long will you sleep? How long will you nap? Soon you will sleep a sleep from which you will not wake until the Day of Resurrection.’”
She [‘Abdah] said: this was her habit all her life, until she died.

Source: http://islamqa.com/en/ref/5994,
From the book "Stories of repentance"