Sunan an-Nasa'i, Volume 3, Book 23, Hadith 2589 (DarusSalam)

It was narrated from Abu Sa'eed Al-Khudri that: some of the Ansar asked the Messenger of Allah (for help) and he gave them (something). Then they asked him and he gave them, then when he had ran out he said: "Whatever I have of good, I will never keep it from you, but whoever wants to refrain from asking, Allah, the Mighty and Sublime, will help him to do so, and whoever wants to be patient, Allah will help him to be patient. None is ever given anything better and more far-reaching than patience."

أَخْبَرَنَا قُتَيْبَةُ، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ عَطَاءِ بْنِ يَزِيدَ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، أَنَّ نَاسًا، مِنَ الأَنْصَارِ سَأَلُوا رَسُولَ اللَّهِ صلى الله عليه وسلم فَأَعْطَاهُمْ ثُمَّ سَأَلُوهُ فَأَعْطَاهُمْ حَتَّى إِذَا نَفِدَ مَا عِنْدَهُ قَالَ ‏ "‏ مَا يَكُونُ عِنْدِي مِنْ خَيْرٍ فَلَنْ أَدَّخِرَهُ عَنْكُمْ وَمَنْ يَسْتَعْفِفْ يُعِفَّهُ اللَّهُ عَزَّ وَجَلَّ وَمَنْ يَصْبِرْ يُصَبِّرْهُ اللَّهُ وَمَا أُعْطِيَ أَحَدٌ عَطَاءً هُوَ خَيْرٌ وَأَوْسَعُ مِنَ الصَّبْرِ ‏" ‏ ‏.‏

sunnah.com