Rabia bin Kaab reported,
The Messenger of Allah ﷺ said to me, "Ask of me, and I shall give you."I said, "Messenger of Allah, give me time to consider my request."He said, "Take your time."I thought it over and said to myself, "The affairs of this world come to an end, so I see nothing better than asking for something that will benefit me in my Hereafter."So I went to the Prophet ﷺ, and he asked, "What is your need?"I said, "Messenger of Allah, intercede for me with your Lord 
that He may free me from the Fire."He asked, "Who instructed you to ask this?"I said, "By Allah, Messenger of Allah, no one instructed me. But I considered my situation and realized that this world will pass away from its people, so I wished to secure something for my Hereafter."He said, "Then help me to help you by making frequent prostration."
Azami 932
Hasanعن ربيعة بن كعب، قال
قال لي رسول الله ﷺ: سلني أعطك. قلت: يا رسول الله، أنظرني أنظر في أمري. قال: انظر في أمرك. قال: نظرت، قلت: إن أمر الدنيا ينقطع، فلا أرى شيئا خيرا من شيء آخذه لنفسي لآخرتي. فدخلت على النبي ﷺ فقال: ما حاجتك؟ قلت: يا رسول الله، اشفع لي إلى ربك عز وجل، فليعتقني من النار، فقال: من أمرك بهذا؟ قلت: لا والله يا رسول الله، ما أمرني به أحد، ولكني نظرت في أمري، فرأيت أن الدنيا زائلة من أهلها، حبيت أن أتخذ لآخرتي. قال: فاعني على نفسك بكثرة السجود.
Imam Ahmad narrated it (16578) from Abu Yaman, who said, Ismail bin Ayyash narrated to us, from Muhammad bin Ishaq, from Muhammad bin Amr bin Ata, from Nuaym bin Mujmirah, from Rabia. This chain contains Ismail bin Ayyash, who is daif in his narration from those who are not from his own region, and this is one such case, though he is corroborated. Muhammad bin Ishaq is a mudallis, but he stated clearly that he heard directly in the following narration.That is what Imam Ahmad narrated (16579) from Yaqub, who said, my father narrated to us, from Ibn Ishaq, who said, Muhammad bin Amr bin Ata narrated to me, from Nuaym bin Mujmir, from Rabia bin Kaab, who said,"I used to serve the Messenger of Allah ﷺ and attend to his needs throughout my day, until the Messenger of Allah ﷺ prayed the last night prayer. Then I would sit by his door when he entered his house, saying to myself, 'Perhaps the Messenger of Allah ﷺ will have some need.' I kept hearing the Messenger of Allah ﷺ saying, 'Glory be to Allah, glory be to Allah, glory be to Allah and praise be to Him,' until I grew tired, so I would either go back or my eyes would overcome me and I would fall asleep.One day, seeing my readiness to serve him and my attendance upon him, he said to me, 'Ask me, Rabia, and I will give you.' I said, 'Let me consider my situation, Messenger of Allah, then I will let you know.'So I thought to myself, and I realized that this world is fleeting and passing away, and that I have a provision in it that will suffice me and will come to me. I said, 'I will ask the Messenger of Allah ﷺ for something for my hereafter, for he holds with Allah the standing that he holds.'So I came to him, and he said, 'What have you decided, Rabia?' I said, 'Yes, Messenger of Allah, I ask you to intercede for me with your Lord, so that He may free me from the Fire.'He said, 'Who told you to say this, Rabia?' I said, 'No, by the One who sent you with the truth, no one told me to say this, but when you said, "Ask me and I will give you," and since you hold with Allah the standing that you hold, I considered my situation and realized that this world is fleeting and passing away, and that I have a provision in it that will come to me. So I said, I will ask the Messenger of Allah ﷺ for something for my hereafter.'The Messenger of Allah ﷺ remained silent for a long while, then said to me, 'I will do so, but help me for your own sake by increasing your sujud.'"