Rabi’ah Ibn Ka’b reports: “Once, the Noble Prophet (S) said to me: “O’ Rabi’ah! You have been serving me for seven years and therefore, will you not ask for something from me in order that I grant it to you?”
“O’ Prophet of Allah! Grant me some time in order that I may reflect over the matter,” I requested. The next day, when I had arrived in his presence, the Prophet (S) said: “O’ Rabi’ah! Speak out your wish.”
“Pray to Allah that He makes me enter Paradise along with you!” I said.
Hearing this request, he inquired, “Who is it that has taught you to seek this from me?”
“No one has taught it to me. I considered that if I sought great wealth, it would eventually get exhausted; if I sought a long life and numerous children, the ultimate eventuality would be death; hence, as a result of this contemplation, I eventually opted for this request,” I replied.
The Noble Prophet (S) lowered his head for a few moments as he deliberated, after which, raising his head, he said: “I shall seek your wish from Allah, but you must help me too (in this matter) by prostrating excessively.”( Khazinatul Jawahir, Page 345; Al-Da’wat (By Rawandi) )