Sunan an-Nasa'i 697
It was narrated from Ibn Abi Sa'eed Al-Khudri that his father said:
"Two men argued about the Masjid which was founded on piety from the first day. [1] One man said that it was the Masjid of Quba', and the other said that it was the Masjid of the Messenger of Allah (ﷺ). The Messenger of Allah (ﷺ) said: 'It is this Masjid of mine.'"

[1] At-Tawbah 9:108.
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ عِمْرَانَ بْنِ أَبِي أَنَسٍ، عَنِ ابْنِ أَبِي سَعِيدٍ الْخُدْرِيِّ، عَنْ أَبِيهِ، قَالَ تَمَارَى رَجُلاَنِ فِي الْمَسْجِدِ الَّذِي أُسِّسَ عَلَى التَّقْوَى مِنْ أَوَّلِ يَوْمٍ فَقَالَ رَجُلٌ هُوَ مَسْجِدُ قُبَاءٍ وَقَالَ الآخَرُ هُوَ مَسْجِدُ رَسُولِ اللَّهِ صلى الله عليه وسلم ‏.‏ فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏
"‏ هُوَ مَسْجِدِي هَذَا ‏"‏ ‏.‏